Get the image file name of any process from any user on Vista and above

On Vista and above there is an information class for NtQuerySystemInformation which I call SystemProcessImageNameInformation (88). (Note that I reverse-engineered this, so it is probably not the correct name for the information class.) The structure definition is below:

typedef struct _SYSTEM_PROCESS_IMAGE_NAME_INFORMATION
{
    HANDLE ProcessId;
    UNICODE_STRING ImageName;
} SYSTEM_PROCESS_IMAGE_NAME_INFORMATION, *PSYSTEM_PROCESS_IMAGE_NAME_INFORMATION;

This information class allows you to get the image file name of any process, regardless of your user, privileges, or access to the process. Usage:

NTSTATUS status;
PVOID buffer;
SYSTEM_PROCESS_IMAGE_NAME_INFORMATION info;

buffer = malloc(0x100);
info.ProcessId = WhateverTheProcessIdIs;
info.ImageName.Length = 0;
info.ImageName.MaximumLength = (USHORT)0x100;
info.ImageName.Buffer = buffer;

status = NtQuerySystemInformation(88, &info, sizeof(info), NULL);

if (status == STATUS_INFO_LENGTH_MISMATCH)
{
    // Our buffer was too small. The required buffer length is stored in MaximumLength.
    free(buffer);
    buffer = malloc(info.ImageName.MaximumLength);
    info.ImageName.Buffer = buffer;
    status = NtQuerySystemInformation(88, &info, sizeof(info), NULL);
}

if (NT_SUCCESS(status))
{
    wprintf(L"File name: %.*s\n", info.ImageName.Length / 2, info.ImageName.Buffer);
}

free(buffer);

4 Comments

  1. wj32,

    The correct name of structure is SystemProcessIdInformation.

    Here are the rest as well:

    enum _SYSTEM_INFORMATION_CLASS {
    SystemBasicInformation = 0x0,
    SystemProcessorInformation = 0x1,
    SystemPerformanceInformation = 0x2,
    SystemTimeOfDayInformation = 0x3,
    SystemPathInformation = 0x4,
    SystemProcessInformation = 0x5,
    SystemCallCountInformation = 0x6,
    SystemDeviceInformation = 0x7,
    SystemProcessorPerformanceInformation = 0x8,
    SystemFlagsInformation = 0x9,
    SystemCallTimeInformation = 0xa,
    SystemModuleInformation = 0xb,
    SystemLocksInformation = 0xc,
    SystemStackTraceInformation = 0xd,
    SystemPagedPoolInformation = 0xe,
    SystemNonPagedPoolInformation = 0xf,
    SystemHandleInformation = 0x10,
    SystemObjectInformation = 0x11,
    SystemPageFileInformation = 0x12,
    SystemVdmInstemulInformation = 0x13,
    SystemVdmBopInformation = 0x14,
    SystemFileCacheInformation = 0x15,
    SystemPoolTagInformation = 0x16,
    SystemInterruptInformation = 0x17,
    SystemDpcBehaviorInformation = 0x18,
    SystemFullMemoryInformation = 0x19,
    SystemLoadGdiDriverInformation = 0x1a,
    SystemUnloadGdiDriverInformation = 0x1b,
    SystemTimeAdjustmentInformation = 0x1c,
    SystemSummaryMemoryInformation = 0x1d,
    SystemMirrorMemoryInformation = 0x1e,
    SystemPerformanceTraceInformation = 0x1f,
    SystemObsolete0 = 0x20,
    SystemExceptionInformation = 0x21,
    SystemCrashDumpStateInformation = 0x22,
    SystemKernelDebuggerInformation = 0x23,
    SystemContextSwitchInformation = 0x24,
    SystemRegistryQuotaInformation = 0x25,
    SystemExtendServiceTableInformation = 0x26,
    SystemPrioritySeperation = 0x27,
    SystemVerifierAddDriverInformation = 0x28,
    SystemVerifierRemoveDriverInformation = 0x29,
    SystemProcessorIdleInformation = 0x2a,
    SystemLegacyDriverInformation = 0x2b,
    SystemCurrentTimeZoneInformation = 0x2c,
    SystemLookasideInformation = 0x2d,
    SystemTimeSlipNotification = 0x2e,
    SystemSessionCreate = 0x2f,
    SystemSessionDetach = 0x30,
    SystemSessionInformation = 0x31,
    SystemRangeStartInformation = 0x32,
    SystemVerifierInformation = 0x33,
    SystemVerifierThunkExtend = 0x34,
    SystemSessionProcessInformation = 0x35,
    SystemLoadGdiDriverInSystemSpace = 0x36,
    SystemNumaProcessorMap = 0x37,
    SystemPrefetcherInformation = 0x38,
    SystemExtendedProcessInformation = 0x39,
    SystemRecommendedSharedDataAlignment = 0x3a,
    SystemComPlusPackage = 0x3b,
    SystemNumaAvailableMemory = 0x3c,
    SystemProcessorPowerInformation = 0x3d,
    SystemEmulationBasicInformation = 0x3e,
    SystemEmulationProcessorInformation = 0x3f,
    SystemExtendedHandleInformation = 0x40,
    SystemLostDelayedWriteInformation = 0x41,
    SystemBigPoolInformation = 0x42,
    SystemSessionPoolTagInformation = 0x43,
    SystemSessionMappedViewInformation = 0x44,
    SystemHotpatchInformation = 0x45,
    SystemObjectSecurityMode = 0x46,
    SystemWatchdogTimerHandler = 0x47,
    SystemWatchdogTimerInformation = 0x48,
    SystemLogicalProcessorInformation = 0x49,
    SystemWow64SharedInformationObsolete = 0x4a,
    SystemRegisterFirmwareTableInformationHandler = 0x4b,
    SystemFirmwareTableInformation = 0x4c,
    SystemModuleInformationEx = 0x4d,
    SystemVerifierTriageInformation = 0x4e,
    SystemSuperfetchInformation = 0x4f,
    SystemMemoryListInformation = 0x50,
    SystemFileCacheInformationEx = 0x51,
    SystemThreadPriorityClientIdInformation = 0x52,
    SystemProcessorIdleCycleTimeInformation = 0x53,
    SystemVerifierCancellationInformation = 0x54,
    SystemProcessorPowerInformationEx = 0x55,
    SystemRefTraceInformation = 0x56,
    SystemSpecialPoolInformation = 0x57,
    SystemProcessIdInformation = 0x58,
    SystemErrorPortInformation = 0x59,
    SystemBootEnvironmentInformation = 0x5a,
    SystemHypervisorInformation = 0x5b,
    SystemVerifierInformationEx = 0x5c,
    SystemTimeZoneInformation = 0x5d,
    SystemImageFileExecutionOptionsInformation = 0x5e,
    SystemCoverageInformation = 0x5f,
    SystemPrefetchPatchInformation = 0x60,
    SystemVerifierFaultsInformation = 0x61,
    SystemSystemPartitionInformation = 0x62,
    SystemSystemDiskInformation = 0x63,
    SystemProcessorPerformanceDistribution = 0x64,
    SystemNumaProximityNodeInformation = 0x65,
    SystemDynamicTimeZoneInformation = 0x66,
    SystemCodeIntegrityInformation = 0x67,
    SystemProcessorMicrocodeUpdateInformation = 0x68,
    SystemProcessorBrandString = 0x69,
    SystemVirtualAddressInformation = 0x6a,
    MaxSystemInfoClass = 0x6b,
    };

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