CheckRemoteDebuggerPresent

Created the Monday 18 March 2019. Updated 3 years, 10 months ago.

CheckRemoteDebuggerPresent is a kernel32.dll function that sets (-1)0xffffffff in the DebuggerPresent parameter if a debugger is present. Internally, it also uses NtQueryInformationProcess with ProcessDebugPort as a ProcessInformationClass parameter.

Technique Identifier

U0121

Code Snippets

#include "windows.h"
 
int main(void)
{
    BOOL HasDebugPort = FALSE;
 
    if (CheckRemoteDebuggerPresent(GetCurrentProcess(), &HasDebugPort))
    {
           ExitProcess(0); // Running in ring-3 debugger
    }
    // Running outside ring-3 debugger
    return 0;

Detection Rules

                                    rule:
  meta:
    name: check for debugger via API
    namespace: anti-analysis/anti-debugging/debugger-detection
    author: michael.hunhoff@fireeye.com
    scope: function
    mbc:
      - Anti-Behavioral Analysis::Debugger Detection::CheckRemoteDebuggerPresent [B0001.002]
      - Anti-Behavioral Analysis::Debugger Detection::WudfIsAnyDebuggerPresent [B0001.031]
    references:
      - https://github.com/LordNoteworthy/al-khaser/blob/master/al-khaser/AntiDebug/CheckRemoteDebuggerPresent.cpp
    examples:
      - al-khaser_x86.exe_:0x420000
  features:
    - or:
      - api: kernel32.CheckRemoteDebuggerPresent
      - api: WUDFPlatform.WudfIsAnyDebuggerPresent
      - api: WUDFPlatform.WudfIsKernelDebuggerPresent
      - api: WUDFPlatform.WudfIsUserDebuggerPresent

Additional Resources

External Links

The resources provided below are associated links that will give you even more detailed information and research on current evasion technique. It is important to note that, while these resources may be helpful, it is important to exercise caution when following external links. As always, be careful when clicking on links from unknown sources, as they may lead to malicious content.

CheckRemoteDebuggerPresent function (debugapi.h) - Win32 apps | Microsoft Docs