NtQueryInformationProcess

NTSTATUS WINAPI NtQueryInformationProcess(
  _In_      HANDLE           ProcessHandle,
  _In_      PROCESSINFOCLASS ProcessInformationClass,
  _Out_     PVOID            ProcessInformation,
  _In_      ULONG            ProcessInformationLength,
  _Out_opt_ PULONG           ReturnLength
);

ProcessInformationClass [in]

ProcessBasicInformation =0
Retrieves a pointer to a PEB structure that can be used to determine whether the specified process is being debugged, and a unique value used by the system to identify the specified process.

ProcessDebugPort =7
Retrieves a DWORD_PTR value that is the port number of the debugger for the process. A nonzero value indicates that the process is being run under the control of a ring 3 debugger.

ProcessDebugObjectHandle =30
ProcessDebugFlags =31

DWORD dwDebugPort = 0;
NtQueryInformationProcess(GetCurrentProcess(),
ProcessDebugPort,
&dwDebugPort,
sizeof(dwDebugPort),
NULL);

NTSTATUS WINAPI ZwQueryInformationProcess(
  _In_      HANDLE           ProcessHandle,
  _In_      PROCESSINFOCLASS ProcessInformationClass,
  _Out_     PVOID            ProcessInformation,
  _In_      ULONG            ProcessInformationLength,
  _Out_opt_ PULONG           ReturnLength
);