- 1 year ago
Use NtQueryInformationProcess to check for debugger attached
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To check if a debugger is attached to a process using the NtQueryInformationProcess
function, you can follow these steps:
- Load the
ntdll.dll
library:
cppHMODULE ntdll = LoadLibrary(L"ntdll.dll");
- Define the function prototype for
NtQueryInformationProcess
:
cpptypedef NTSTATUS(WINAPI* pfnNtQueryInformationProcess)(
HANDLE ProcessHandle,
PROCESSINFOCLASS ProcessInformationClass,
PVOID ProcessInformation,
ULONG ProcessInformationLength,
PULONG ReturnLength
);
- Retrieve the address of the
NtQueryInformationProcess
function:
cpppfnNtQueryInformationProcess NtQueryInformationProcessPtr =
(pfnNtQueryInformationProcess)GetProcAddress(ntdll, "NtQueryInformationProcess");
- Obtain a handle to the target process:
cppHANDLE hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, processId);
Note: Replace processId
with the actual process ID of the target process.
- Call
NtQueryInformationProcess
with theProcessDebugPort
information class to retrieve debugger-related information:
cppULONG_PTR debugPort = 0;
NTSTATUS status = NtQueryInformationProcessPtr(
hProcess,
ProcessDebugPort,
&debugPort,
sizeof(debugPort),
nullptr
);
- Check the
debugPort
value to determine if a debugger is attached:
cppif (debugPort != 0)
{
// Debugger is attached
}
else
{
// No debugger is attached
}
- Close the process handle when you're done:
cppCloseHandle(hProcess);
Remember to handle errors and perform appropriate error checking throughout the code.
Please note that using undocumented functions like NtQueryInformationProcess
is not officially supported by Microsoft, and its behavior may change in future Windows versions.