The VX-API is a collection of malicious functionality to aid in malware development. It is recommended you clone and/or download this entire repo then open the Visual Studio solution file to easily explore functionality and concepts.
Some functions may be dependent on other functions present within the solution file. Using the solution file provided here will make it easier to identify which other functionality and/or header data is required.
You're free to use this in any manner you please. You do not need to use this entire solution for your malware proof-of-concepts or Red Team engagements. Strip, copy, paste, delete, or edit this projects contents as much as you'd like.
Function Name | Original Author |
---|---|
AdfCloseHandleOnInvalidAddress | Checkpoint Research |
AdfIsCreateProcessDebugEventCodeSet | Checkpoint Research |
AdfOpenProcessOnCsrss | Checkpoint Research |
CheckRemoteDebuggerPresent2 | ReactOS |
IsDebuggerPresentEx | smelly__vx |
IsIntelHardwareBreakpointPresent | Checkpoint Research |
Function Name | Original Author |
---|---|
HashStringDjb2 | Dan Bernstein |
HashStringFowlerNollVoVariant1a | Glenn Fowler, Landon Curt Noll, and Kiem-Phong Vo |
HashStringJenkinsOneAtATime32Bit | Bob Jenkins |
HashStringLoseLose | Brian Kernighan and Dennis Ritchie |
HashStringRotr32 | T. Oshiba (1972) |
HashStringSdbm | Ozan Yigit |
HashStringSuperFastHash | Paul Hsieh |
HashStringUnknownGenericHash1A | Unknown |
HashStringSipHash | RistBS |
HashStringMurmur | RistBS |
CreateMd5HashFromFilePath | Microsoft |
CreatePseudoRandomInteger | Apple (c) 1999 |
CreatePseudoRandomString | smelly__vx |
HashFileByMsiFileHashTable | smelly__vx |
CreatePseudoRandomIntegerFromNtdll | smelly__vx |
LzMaximumCompressBuffer | smelly__vx |
LzMaximumDecompressBuffer | smelly__vx |
LzStandardCompressBuffer | smelly__vx |
LzStandardDecompressBuffer | smelly__vx |
XpressHuffMaximumCompressBuffer | smelly__vx |
XpressHuffMaximumDecompressBuffer | smelly__vx |
XpressHuffStandardCompressBuffer | smelly__vx |
XpressHuffStandardDecompressBuffer | smelly__vx |
XpressMaximumCompressBuffer | smelly__vx |
XpressMaximumDecompressBuffer | smelly__vx |
XpressStandardCompressBuffer | smelly__vx |
XpressStandardDecompressBuffer | smelly__vx |
ExtractFilesFromCabIntoTarget | smelly__vx |
Function Name | Original Author |
---|---|
GetLastErrorFromTeb | smelly__vx |
GetLastNtStatusFromTeb | smelly__vx |
RtlNtStatusToDosErrorViaImport | ReactOS |
GetLastErrorFromTeb | smelly__vx |
SetLastErrorInTeb | smelly__vx |
SetLastNtStatusInTeb | smelly__vx |
Win32FromHResult | Raymond Chen |
Function Name | Original Author |
---|---|
AmsiBypassViaPatternScan | ZeroMemoryEx |
DelayedExecutionExecuteOnDisplayOff | am0nsec and smelly__vx |
HookEngineRestoreHeapFree | rad9800 |
MasqueradePebAsExplorer | smelly__vx |
RemoveDllFromPeb | rad9800 |
RemoveRegisterDllNotification | Rad98, Peter Winter-Smith |
SleepObfuscationViaVirtualProtect | 5pider |
RtlSetBaseUnicodeCommandLine | TheWover |
Function Name | Original Author |
---|---|
GetCurrentLocaleFromTeb | 3xp0rt |
GetNumberOfLinkedDlls | smelly__vx |
GetOsBuildNumberFromPeb | smelly__vx |
GetOsMajorVersionFromPeb | smelly__vx |
GetOsMinorVersionFromPeb | smelly__vx |
GetOsPlatformIdFromPeb | smelly__vx |
IsNvidiaGraphicsCardPresent | smelly__vx |
IsProcessRunning | smelly__vx |
IsProcessRunningAsAdmin | Vimal Shekar |
GetPidFromNtQuerySystemInformation | smelly__vx |
GetPidFromWindowsTerminalService | modexp |
GetPidFromWmiComInterface | aalimian and modexp |
GetPidFromEnumProcesses | smelly__vx |
GetPidFromPidBruteForcing | modexp |
GetPidFromNtQueryFileInformation | modexp, Lloyd Davies, Jonas Lyk |
GetPidFromPidBruteForcingExW | smelly__vx, LLoyd Davies, Jonas Lyk, modexp |
Function Name | Original Author |
---|---|
CreateLocalAppDataObjectPath | smelly__vx |
CreateWindowsObjectPath | smelly__vx |
GetCurrentDirectoryFromUserProcessParameters | smelly__vx |
GetCurrentProcessIdFromTeb | ReactOS |
GetCurrentUserSid | Giovanni Dicanio |
GetCurrentWindowTextFromUserProcessParameter | smelly__vx |
GetFileSizeFromPath | smelly__vx |
GetProcessHeapFromTeb | smelly__vx |
GetProcessPathFromLoaderLoadModule | smelly__vx |
GetProcessPathFromUserProcessParameters | smelly__vx |
GetSystemWindowsDirectory | Geoff Chappell |
IsPathValid | smelly__vx |
RecursiveFindFile | Luke |
SetProcessPrivilegeToken | Microsoft |
IsDllLoaded | smelly__vx |
TryLoadDllMultiMethod | smelly__vx |
CreateThreadAndWaitForCompletion | smelly__vx |
GetProcessBinaryNameFromHwndW | smelly__vx |
GetByteArrayFromFile | smelly__vx |
Ex_GetHandleOnDeviceHttpCommunication | x86matthew |
IsRegistryKeyValid | smelly__vx |
FastcallExecuteBinaryShellExecuteEx | smelly__vx |
GetCurrentProcessIdFromOffset | RistBS |
GetPeBaseAddress | smelly__vx |
LdrLoadGetProcedureAddress | c5pider |
IsPeSection | smelly__vx |
AddSectionToPeFile | smelly__vx |
WriteDataToPeSection | smelly__vx |
GetPeSectionSizeInByte | smelly__vx |
ReadDataFromPeSection | smelly__vx |
GetCurrentProcessNoForward | ReactOS |
GetCurrentThreadNoForward | ReactOS |
Function Name | Original Author |
---|---|
GetKUserSharedData | Geoff Chappell |
GetModuleHandleEx2 | smelly__vx |
GetPeb | 29a |
GetPebFromTeb | ReactOS |
GetProcAddress | 29a Volume 2, c5pider |
GetProcAddressDjb2 | smelly__vx |
GetProcAddressFowlerNollVoVariant1a | smelly__vx |
GetProcAddressJenkinsOneAtATime32Bit | smelly__vx |
GetProcAddressLoseLose | smelly__vx |
GetProcAddressRotr32 | smelly__vx |
GetProcAddressSdbm | smelly__vx |
GetProcAddressSuperFastHash | smelly__vx |
GetProcAddressUnknownGenericHash1 | smelly__vx |
GetProcAddressSipHash | RistBS |
GetProcAddressMurmur | RistBS |
GetRtlUserProcessParameters | ReactOS |
GetTeb | ReactOS |
RtlLoadPeHeaders | smelly__vx |
ProxyWorkItemLoadLibrary | Rad98, Peter Winter-Smith |
ProxyRegisterWaitLoadLibrary | Rad98, Peter Winter-Smith |
Function Name | Original Author |
---|---|
MpfGetLsaPidFromServiceManager | modexp |
MpfGetLsaPidFromRegistry | modexp |
MpfGetLsaPidFromNamedPipe | modexp |
Function Name | Original Author |
---|---|
UrlDownloadToFileSynchronous | Hans Passant |
ConvertIPv4IpAddressStructureToString | smelly__vx |
ConvertIPv4StringToUnsignedLong | smelly__vx |
SendIcmpEchoMessageToIPv4Host | smelly__vx |
ConvertIPv4IpAddressUnsignedLongToString | smelly__vx |
DnsGetDomainNameIPv4AddressAsString | smelly__vx |
DnsGetDomainNameIPv4AddressUnsignedLong | smelly__vx |
GetDomainNameFromUnsignedLongIPV4Address | smelly__vx |
GetDomainNameFromIPV4AddressAsString | smelly__vx |
Function Name | Original Author |
---|---|
OleGetClipboardData | Microsoft |
MpfComVssDeleteShadowVolumeBackups | am0nsec |
MpfComModifyShortcutTarget | Unknown |
MpfComMonitorChromeSessionOnce | smelly__vx |
MpfExtractMaliciousPayloadFromZipFileNoPassword | Codu |
Function Name | Original Author |
---|---|
CreateProcessFromIHxHelpPaneServer | James Forshaw |
CreateProcessFromIHxInteractiveUser | James Forshaw |
CreateProcessFromIShellDispatchInvoke | Mohamed Fakroud |
CreateProcessFromShellExecuteInExplorerProcess | Microsoft |
CreateProcessViaNtCreateUserProcess | CaptMeelo |
CreateProcessWithCfGuard | smelly__vx and Adam Chester |
CreateProcessByWindowsRHotKey | smelly__vx |
CreateProcessByWindowsRHotKeyEx | smelly__vx |
CreateProcessFromINFSectionInstallStringNoCab | smelly__vx |
CreateProcessFromINFSetupCommand | smelly__vx |
CreateProcessFromINFSectionInstallStringNoCab2 | smelly__vx |
CreateProcessFromIeFrameOpenUrl | smelly__vx |
CreateProcessFromPcwUtil | smelly__vx |
CreateProcessFromShdocVwOpenUrl | smelly__vx |
CreateProcessFromShell32ShellExecRun | smelly__vx |
MpfExecute64bitPeBinaryInMemoryFromByteArrayNoReloc | aaaddress1 |
CreateProcessFromWmiWin32_ProcessW | CIA |
CreateProcessFromZipfldrRouteCall | smelly__vx |
CreateProcessFromUrlFileProtocolHandler | smelly__vx |
CreateProcessFromUrlOpenUrl | smelly__vx |
CreateProcessFromMsHTMLW | smelly__vx |
Function Name | Original Author |
---|---|
MpfPiControlInjection | SafeBreach Labs |
MpfPiQueueUserAPCViaAtomBomb | SafeBreach Labs |
MpfPiWriteProcessMemoryCreateRemoteThread | SafeBreach Labs |
MpfProcessInjectionViaProcessReflection | Deep Instinct |
Function Name | Original Author |
---|---|
IeCreateFile | smelly__vx |
CopyFileViaSetupCopyFile | smelly__vx |
CreateFileFromDsCopyFromSharedFile | Jonas Lyk |
DeleteDirectoryAndSubDataViaDelNode | smelly__vx |
DeleteFileWithCreateFileFlag | smelly__vx |
IsProcessRunningAsAdmin2 | smelly__vx |
IeCreateDirectory | smelly__vx |
IeDeleteFile | smelly__vx |
IeFindFirstFile | smelly__vx |
IEGetFileAttributesEx | smelly__vx |
IeMoveFileEx | smelly__vx |
IeRemoveDirectory | smelly__vx |
Function Name | Original Author |
---|---|
MpfSceViaImmEnumInputContext | alfarom256, aahmad097 |
MpfSceViaCertFindChainInStore | alfarom256, aahmad097 |
MpfSceViaEnumPropsExW | alfarom256, aahmad097 |
MpfSceViaCreateThreadpoolWait | alfarom256, aahmad097 |
MpfSceViaCryptEnumOIDInfo | alfarom256, aahmad097 |
MpfSceViaDSA_EnumCallback | alfarom256, aahmad097 |
MpfSceViaCreateTimerQueueTimer | alfarom256, aahmad097 |
MpfSceViaEvtSubscribe | alfarom256, aahmad097 |
MpfSceViaFlsAlloc | alfarom256, aahmad097 |
MpfSceViaInitOnceExecuteOnce | alfarom256, aahmad097 |
MpfSceViaEnumChildWindows | alfarom256, aahmad097, wra7h |
MpfSceViaCDefFolderMenu_Create2 | alfarom256, aahmad097, wra7h |
MpfSceViaCertEnumSystemStore | alfarom256, aahmad097, wra7h |
MpfSceViaCertEnumSystemStoreLocation | alfarom256, aahmad097, wra7h |
MpfSceViaEnumDateFormatsW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumDesktopWindows | alfarom256, aahmad097, wra7h |
MpfSceViaEnumDesktopsW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumDirTreeW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumDisplayMonitors | alfarom256, aahmad097, wra7h |
MpfSceViaEnumFontFamiliesExW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumFontsW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumLanguageGroupLocalesW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumObjects | alfarom256, aahmad097, wra7h |
MpfSceViaEnumResourceTypesExW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumSystemCodePagesW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumSystemGeoID | alfarom256, aahmad097, wra7h |
MpfSceViaEnumSystemLanguageGroupsW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumSystemLocalesEx | alfarom256, aahmad097, wra7h |
MpfSceViaEnumThreadWindows | alfarom256, aahmad097, wra7h |
MpfSceViaEnumTimeFormatsEx | alfarom256, aahmad097, wra7h |
MpfSceViaEnumUILanguagesW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumWindowStationsW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumWindows | alfarom256, aahmad097, wra7h |
MpfSceViaEnumerateLoadedModules64 | alfarom256, aahmad097, wra7h |
MpfSceViaK32EnumPageFilesW | alfarom256, aahmad097, wra7h |
MpfSceViaEnumPwrSchemes | alfarom256, aahmad097, wra7h |
MpfSceViaMessageBoxIndirectW | alfarom256, aahmad097, wra7h |
MpfSceViaChooseColorW | alfarom256, aahmad097, wra7h |
MpfSceViaClusWorkerCreate | alfarom256, aahmad097, wra7h |
MpfSceViaSymEnumProcesses | alfarom256, aahmad097, wra7h |
MpfSceViaImageGetDigestStream | alfarom256, aahmad097, wra7h |
MpfSceViaVerifierEnumerateResource | alfarom256, aahmad097, wra7h |
MpfSceViaSymEnumSourceFiles | alfarom256, aahmad097, wra7h |
Function Name | Original Author |
---|---|
ByteArrayToCharArray | smelly__vx |
CharArrayToByteArray | smelly__vx |
ShlwapiCharStringToWCharString | smelly__vx |
ShlwapiWCharStringToCharString | smelly__vx |
CharStringToWCharString | smelly__vx |
WCharStringToCharString | smelly__vx |
RtlInitEmptyUnicodeString | ReactOS |
RtlInitUnicodeString | ReactOS |
CaplockString | simonc |
CopyMemoryEx | ReactOS |
SecureStringCopy | Apple (c) 1999 |
StringCompare | Apple (c) 1999 |
StringConcat | Apple (c) 1999 |
StringCopy | Apple (c) 1999 |
StringFindSubstring | Apple (c) 1999 |
StringLength | Apple (c) 1999 |
StringLocateChar | Apple (c) 1999 |
StringRemoveSubstring | smelly__vx |
StringTerminateStringAtChar | smelly__vx |
StringToken | Apple (c) 1999 |
ZeroMemoryEx | ReactOS |
ConvertCharacterStringToIntegerUsingNtdll | smelly__vx |
MemoryFindMemory | KamilCuk |
Function Name | Original Author |
---|---|
UacBypassFodHelperMethod | winscripting.blog |
Function Name | Original Author |
---|---|
InitHardwareBreakpointEngine | rad98 |
ShutdownHardwareBreakpointEngine | rad98 |
ExceptionHandlerCallbackRoutine | rad98 |
SetHardwareBreakpoint | rad98 |
InsertDescriptorEntry | rad98 |
RemoveDescriptorEntry | rad98 |
SnapshotInsertHardwareBreakpointHookIntoTargetThread | rad98 |
Function Name | Original Author |
---|---|
GenericShellcodeHelloWorldMessageBoxA | SafeBreach Labs |
GenericShellcodeHelloWorldMessageBoxAEbFbLoop | SafeBreach Labs |
GenericShellcodeOpenCalcExitThread | MsfVenom |
YARA rule Analyzer to improve rule quality and performance
YARA rules can be syntactically correct but still dysfunctional. yaraQA tries to find and report these issues to the author or maintainer of a YARA rule set.
The issues yaraQA tries to detect are e.g.:
2 of them
in the condition)$ = "\\Debug\\" fullword
)$ = "AA"
; can be excluded from the analysis using --ignore-performance
)I'm going to extend the test set over time. Each minor version will include new features or new tests.
pip install -r requirements.txt
usage: yaraQA.py [-h] [-f yara files [yara files ...]] [-d yara files [yara files ...]] [-o outfile] [-b baseline] [-l level]
[--ignore-performance] [--debug]
YARA RULE ANALYZER
optional arguments:
-h, --help show this help message and exit
-f yara files [yara files ...]
Path to input files (one or more YARA rules, separated by space)
-d yara files [yara files ...]
Path to input directory (YARA rules folders, separated by space)
-o outfile Output file that lists the issues (JSON, default: 'yaraQA-issues.json')
-b baseline Use a issues baseline (issues found and reviewed before) to filter issues
-l level Minium level to show (1=informational, 2=warning, 3=critical)
--ignore-performance Suppress performance-related rule issues
--debug Debug output
python3 yaraQA.py -d ./test/
Suppress all performance issues and only show detection / logic issues.
python3 yaraQA.py -d ./test/ --ignore-performance
Suppress all issues of informational character
python3 yaraQA.py -d ./test/ -level 2
Use a baseline to only see new issues (not the ones that you've already reviewed). The baseline file is an old JSON output of a reviewed state.
python3 yaraQA.py -d ./test/ -b yaraQA-reviewed-issues.json
Example rules with issues can be found in the ./test
folder.
yaraQA writes the detected issues to a file named yaraQA-issues.json
by default.
This listing shows an example of the output generated by yaraQA in JSON format:
[
{
"rule": "Demo_Rule_1_Fullword_PDB",
"id": "SM1",
"issue": "The rule uses a PDB string with the modifier 'wide'. PDB strings are always included as ASCII strings. The 'wide' keyword is unneeded.",
"element": {
"name": "$s1",
"value": "\\\\i386\\\\mimidrv.pdb",
"type": "text",
"modifiers": [
"ascii",
"wide",
"fullword"
]
},
"level": "info",
"type": "logic",
"recommendation": "Remove the 'wide' modifier"
},
{
"rule": "Demo_Rule_1_Fullword_PDB",
"id": "SM2",
"issue": "The rule uses a PDB string with the modifier 'fullword' but it starts with two backslashes and thus the modifier could lead to a dysfunctional rule.",
"element": {
"name": " $s1",
"value": "\\\\i386\\\\mimidrv.pdb",
"type": "text",
"modifiers": [
"ascii",
"wide",
"fullword"
]
},
"level": "warning",
"type": "logic",
"recommendation": "Remove the 'fullword' modifier"
},
{
"rule": "Demo_Rule_2_Short_Atom",
"id": "PA2",
"issue": "The rule contains a string that turns out to be a very short atom, which could cause a reduced performance of the complete rule set or increased memory usage.",
"element": {
"name": "$s1",
"value": "{ 01 02 03 }",
"type": "byte"
},
"level": "warning",
"type": "performance",
"recommendation": "Try to avoid using such short atoms, by e.g. adding a few more bytes to the beginning or the end (e.g. add a binary 0 in front or a space after the string). Every additional byte helps."
},
{
"rule": "Demo_Rule_3_Fullword_FilePath_Section",
"id": "SM3",
"issue": "The rule uses a string with the modifier 'fullword' but it starts and ends with two backslashes and thus the modifier could lead to a dysfunctional rule.",
"element": {
"name": "$s1",
"value": "\\\\ZombieBoy\\\\",
"type": "text",
"modifiers": [
"ascii",
"fullword"
]
},
"level": "warning",
"type": "logic",
"recommendation": "Remove the 'fullword' modifier"
},
{
"rule": "Demo_Rule_4_Condition_Never_Matches",
"id": "CE1",
"issue": "The rule uses a condition that will never match",
"element": {
"condition_segment": "2 of",
"num_of_strings": 1
},
"level": "error",
"type": "logic",
"recommendation": "Fix the condition"
},
{
"rule": "Demo_Rule_5_Condition_Short_String_At_Pos",
"id": "PA1",
"issue": "This rule looks for a short string at a particular position. A short string represents a short atom and could be rewritten to an expression using uint(x) at position.",
"element": {
"condition_segment": "$mz at 0",
"string": "$mz",
"value": "MZ"
},
"level": "warning",
"type": "performance",
"recommendation": ""
},
{
"rule": "Demo_Rule_5_Condition_Short_String_At_Pos",
"id": "PA2",
"issue": "The rule contains a string that turns out to be a very short atom, which could cause a reduced performance of the complete rule set or increased memory usage.",< br/> "element": {
"name": "$mz",
"value": "MZ",
"type": "text",
"modifiers": [
"ascii"
]
},
"level": "warning",
"type": "performance",
"recommendation": "Try to avoid using such short atoms, by e.g. adding a few more bytes to the beginning or the end (e.g. add a binary 0 in front or a space after the string). Every additional byte helps."
},
{
"rule": "Demo_Rule_6_Condition_Short_Byte_At_Pos",
"id": "PA1",
"issue": "This rule looks for a short string at a particular position. A short string represents a short atom and could be rewritten to an expression using uint(x) at position.",
"element": {
"condition_segment": "$mz at 0",
"string": "$mz",
"value": "{ 4d 5a }"
},
"level": "warning",
"type": "performance",
"recommendation": ""
},
{
"rule": "Demo_Rule_6_Condition_Short_Byte_At_Pos",
"id": "PA2",
"issue": "The rule contains a string that turns out to be a very short atom, which could cause a reduced performance of the complete rule set or increased memory usage.",
"element": {
"name": "$mz",
"value": "{ 4d 5a }",
"type": "byte"
},
"level": "warning",
"type": "performance",
"recommendation": "Try to avoid using such short atoms, by e.g. adding a few more bytes to the beginning or the end (e.g. add a binary 0 in front or a space after the string). Every additional byte helps."
},
{
"rule": "Demo_Rule_6_Condition_Short_Byte_At_Pos",
"id": "SM3",
"issue": "The rule uses a string with the modifier 'fullword' but it starts and ends with two backsla shes and thus the modifier could lead to a dysfunctional rule.",
"element": {
"name": "$s1",
"value": "\\\\Section\\\\in\\\\Path\\\\",
"type": "text",
"modifiers": [
"ascii",
"fullword"
]
},
"level": "warning",
"type": "logic",
"recommendation": "Remove the 'fullword' modifier"
}
]
Handle hijacking is a technique used in Windows operating systems to gain access to resources and resources of a system without permission. It is a type of privilege escalation attack in which a malicious user takes control of an object handle, which is an identifier that is used to reference a system object, such as a file, a directory, a process, or an event. This allows the malicious user to gain access to resources that should be inaccessible to them.
Handle hijacking is a serious threat to system security as it allows a malicious user to access resources and data that should otherwise be protected. It can also be used to inject code into a vulnerable system, allowing the attacker to gain access to information and resources.
Handle hijacking techniques are becoming increasingly prevalent as hackers develop more sophisticated methods of exploiting vulnerabilities in Windows systems. As such, it is important that system administrators understand the risks associated with handle hijacking and take proactive measures to protect their systems.
To perform a handle hijacking attack, an attacker must first identify a handle that is being used by a legitimate process and that they want to access. This can be done using various techniques, such as scanning the handle table of a process, monitoring handle creation events, or using a tool that can enumerate handles on the system ,Once the attacker has identified the handle they want to access, they can use the DuplicateHandle
function to create a copy of the handle with their own process. This function takes the following parameters:
hSourceProcessHandle
: A handle to the process that contains the source handle.hSourceHandle
: A handle to the object to duplicate.hTargetProcessHandle
: A handle to the process that is to receive the duplicated handle.lpTargetHandle
: A pointer to a variable that receives the handle value.dwDesiredAccess
: The access rights for the duplicated handle.bInheritHandle
: A value that specifies whether the handle is inheritable.dwOptions
: Additional options for the handle duplication.The DuplicateHandle
function will create a new handle with the specified access rights and options, and return it in the lpTargetHandle
parameter. The attacker can then use this handle to access the resource that it represents, allowing them to perform actions on the resource that they would not normally be able to do.
Sandboxes are commonly used to analyze malware. They provide a temporary, isolated, and secure environment in which to observe whether a suspicious file exhibits any malicious behavior. However, malware developers have also developed methods to evade sandboxes and analysis environments. One such method is to perform checks to determine whether the machine the malware is being executed on is being operated by a real user. One such check is the RAM size. If the RAM size is unrealistically small (e.g., 1GB), it may indicate that the machine is a sandbox. If the malware detects a sandbox, it will not execute its true malicious behavior and may appear to be a benign file
The GetPhysicallyInstalledSystemMemory
API retrieves the amount of RAM that is physically installed on the computer from the SMBIOS firmware tables. It takes a PULONGLONG
parameter and returns TRUE
if the function succeeds, setting the TotalMemoryInKilobytes
to a nonzero value. If the function fails, it returns FALSE
.
The amount of physical memory retrieved by the GetPhysicallyInstalledSystemMemory
function must be equal to or greater than the amount reported by the GlobalMemoryStatusEx
function; if it is less, the SMBIOS data is malformed and the function fails with ERROR_INVALID_DATA
, Malformed SMBIOS data may indicate a problem with the user's computer .
The register rcx
holds the parameter TotalMemoryInKilobytes
. To overwrite the jump address of GetPhysicallyInstalledSystemMemory
, I use the following opcodes: mov qword ptr ss:[rcx],4193B840
. This moves the value 4193B840
(or 1.1 TB) to rcx
. Then, the ret instruction is used to pop the return address off the stack and jump to it, Therefore, whenever GetPhysicallyInstalledSystemMemory
is called, it will set rcx
to the custom value."