一、调试器检测

1.1 IsDebuggerPresent

使用IsDebuggerPresent函数检测PEB的BeingDebugged标志位

BOOL IsDebuggerPresent();

代码

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

// Function to check if a debugger is present
bool IsDebuggerPresentCheck() {
  return IsDebuggerPresent() == TRUE;
}

// Function that simulates the main functionality
void hack() {
  MessageBox(NULL, "Meow!", "=^..^=", MB_OK);
}

int main() {
  // Check if a debugger is present
  if (IsDebuggerPresentCheck()) {
    MessageBox(NULL, "Debugger detected!", "=^..^=", MB_OK);
    return 1;  // exit if a debugger is present
  }
  // Main functionality
  hack();
  return 0;
}

编译

x86_64-w64-mingw32-g++ -O2 hack.c -o hack.exe -I/usr/share/mingw-w64/include/ -s -ffunction-sections -fdata-sections -Wno-write-strings -fno-exceptions -fmerge-all-constants -static-libstdc++ -static-libgcc -fpermissive

windows10上用用x64dbg打开，检测到调试器

1.2 CheckRemoteDebuggerPresent

还有一个函数可以监测调试器附加进程

CheckRemoteDebuggerPresent()

代码

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

// Function to check if a debugger is present
bool DebuggerCheck() {
  BOOL result;
  CheckRemoteDebuggerPresent(GetCurrentProcess(), &result);
  return result;
}

// Function that simulates the main functionality
void hack() {
  MessageBox(NULL, "Meow!", "=^..^=", MB_OK);
}

int main() {
  // Check if a debugger is present
  if (DebuggerCheck()) {
    MessageBox(NULL, "Bow-wow!", "=^..^=", MB_OK);
    return 1;  // exit if a debugger is present
  }
  // Main functionality
  hack();
  return 0;
}

编译

x86_64-w64-mingw32-g++ -O2 hack2.c -o hack2.exe -I/usr/share/mingw-w64/include/ -s -ffunction-sections -fdata-sections -Wno-write-strings -fno-exceptions -fmerge-all-constants -static-libstdc++ -static-libgcc -fpermissive

windows10上使用x64dbg打开，检测出调试器