APT_Backdoor_Win_DShell_2

YARA-2025-1077 High general Active

No description available for this rule

APT_Backdoor_Win_DShell_2.yar Valid Syntax

// Copyright 2020 by FireEye, Inc.
// You may not use this file except in compliance with the license. The license should have been received with this file. You may obtain a copy of the license at:
// https://github.com/fireeye/red_team_tool_countermeasures/blob/master/LICENSE.txt
rule APT_Backdoor_Win_DShell_2
{
    meta:
        description = "This rule looks for strings specific to the D programming language in combination with a selection of Windows functions that are present within a DShell payload"
        md5 = "e0683f8ee787313cfd2c61cd0995a830"
        rev = 4
        author = "FireEye"
    strings:
        $dlang1 = "C:\\D\\dmd2\\windows\\bin\\..\\..\\src\\phobos\\std\\utf.d" ascii wide
        $dlang2 = "C:\\D\\dmd2\\windows\\bin\\..\\..\\src\\phobos\\std\\file.d" ascii wide
        $dlang3 = "C:\\D\\dmd2\\windows\\bin\\..\\..\\src\\phobos\\std\\format.d" ascii wide
        $dlang4 = "C:\\D\\dmd2\\windows\\bin\\..\\..\\src\\phobos\\std\\base64.d" ascii wide
        $dlang5 = "C:\\D\\dmd2\\windows\\bin\\..\\..\\src\\phobos\\std\\stdio.d" ascii wide
        $dlang6 = "\\..\\..\\src\\phobos\\std\\utf.d" ascii wide
        $dlang7 = "\\..\\..\\src\\phobos\\std\\file.d" ascii wide
        $dlang8 = "\\..\\..\\src\\phobos\\std\\format.d" ascii wide
        $dlang9 = "\\..\\..\\src\\phobos\\std\\base64.d" ascii wide
        $dlang10 = "\\..\\..\\src\\phobos\\std\\stdio.d" ascii wide
        $dlang11 = "Unexpected '\\n' when converting from type const(char)[] to type int" ascii wide
        $ign1 = "--strip-comments"
        $ign2 = "Usage: rdmd [RDMD AND DMD OPTIONS]"
        $s1 = "CloseHandle"
        $s2 = "CommandLineToArgvW"
        $s3 = "CreateFileA"
        $s4 = "CreateSemaphoreA"
        $s5 = "CreateThread"
        $s6 = "DeleteCriticalSection"
        $s7 = "DeleteFileA"
        $s8 = "DuplicateHandle"
        $s9 = "EnterCriticalSection"
        $s10 = "ExitProcess"
        $s11 = "ExitThread"
        $s12 = "ExpandEnvironmentStringsW"
        $s13 = "FileTimeToDosDateTime"
        $s14 = "FindClose"
        $s15 = "FindFirstFileA"
        $s16 = "FindFirstFileW"
        $s17 = "FindNextFileA"
        $s18 = "FindNextFileW"
        $s19 = "FormatMessageW"
        $s20 = "FreeEnvironmentStringsA"
        $s21 = "FreeEnvironmentStringsW"
        $s22 = "FreeLibrary"
        $s23 = "GetACP"
        $s24 = "GetCPInfo"
        $s25 = "GetCommandLineA"
        $s26 = "GetCommandLineW"
        $s27 = "GetConsoleOutputCP"
        $s28 = "GetConsoleScreenBufferInfo"
        $s29 = "GetCurrentProcess"
        $s30 = "GetCurrentThread"
        $s31 = "GetCurrentThreadId"
        $s32 = "GetEnvironmentStrings"
        $s33 = "GetEnvironmentStringsW"
        $s34 = "GetEnvironmentVariableA"
        $s35 = "GetEnvironmentVariableW"
        $s36 = "GetExitCodeThread"
        $s37 = "GetFileAttributesW"
        $s38 = "GetFileType"
        $s39 = "GetLastError"
        $s40 = "GetModuleFileNameA"
        $s41 = "GetModuleHandleA"
        $s42 = "GetOEMCP"
        $s43 = "GetProcAddress"
        $s44 = "GetProcessHeap"
        $s45 = "GetStdHandle"
        $s46 = "GetStringTypeA"
        $s47 = "GetSystemInfo"
        $s48 = "GetThreadContext"
        $s49 = "GetTickCount"
        $s50 = "GetTimeZoneInformation"
        $s51 = "GetVersion"
        $s52 = "GlobalAlloc"
        $s53 = "GlobalFree"
        $s54 = "GlobalMemoryStatus"
        $s55 = "HeapAlloc"
        $s56 = "HeapFree"
        $s57 = "HeapReAlloc"
        $s58 = "InitializeCriticalSection"
        $s59 = "IsDebuggerPresent"
        $s60 = "LCMapStringA"
        $s61 = "LeaveCriticalSection"
        $s62 = "LoadLibraryA"
        $s63 = "LoadLibraryW"
        $s64 = "LocalFree"
        $s65 = "MessageBoxA"
        $s66 = "MultiByteToWideChar"
        $s67 = "QueryPerformanceCounter"
        $s68 = "QueryPerformanceFrequency"
        $s69 = "RaiseException"
        $s70 = "ReadFile"
        $s71 = "RegCloseKey"
        $s72 = "RegCreateKeyExW"
        $s73 = "RegDeleteKeyW"
        $s74 = "RegDeleteValueW"
        $s75 = "RegEnumKeyExW"
        $s76 = "RegEnumValueW"
        $s77 = "RegFlushKey"
        $s78 = "RegOpenKeyExW"
        $s79 = "RegOpenKeyW"
        $s80 = "RegQueryInfoKeyW"
        $s81 = "RegQueryValueExW"
        $s82 = "RegSetValueExW"
        $s83 = "ReleaseSemaphore"
        $s84 = "ResumeThread"
        $s85 = "RtlCaptureContext"
        $s86 = "RtlUnwind"
        $s87 = "SetConsoleCtrlHandler"
        $s88 = "SetEnvironmentVariableW"
        $s89 = "SetFilePointer"
        $s90 = "SetHandleCount"
        $s91 = "SetLastError"
        $s92 = "Sleep"
        $s93 = "SuspendThread"
        $s94 = "SwitchToThread"
        $s95 = "SystemTimeToTzSpecificLocalTime"
        $s96 = "TryEnterCriticalSection"
        $s97 = "TzSpecificLocalTimeToSystemTime"
        $s98 = "UnhandledExceptionFilter"
        $s99 = "VirtualAlloc"
        $s100 = "VirtualFree"
        $s101 = "WaitForSingleObject"
        $s102 = "WideCharToMultiByte"
        $s103 = "WriteConsoleA"
        $s104 = "WriteFile"
        $s105 = "lstrlenW"
    condition:
        (uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and filesize > 500KB and filesize > 700KB and all of ($s*) and 1 of ($dlang*) and not $ign1 and not $ign2
}

String Definitions

{"name":"$dlang1","value":"\"C:\\\\D\\\\dmd2\\\\windows\\\\bin\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\utf.d\" ascii wide"}

{"name":"$dlang2","value":"\"C:\\\\D\\\\dmd2\\\\windows\\\\bin\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\file.d\" ascii wide"}

{"name":"$dlang3","value":"\"C:\\\\D\\\\dmd2\\\\windows\\\\bin\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\format.d\" ascii wide"}

{"name":"$dlang4","value":"\"C:\\\\D\\\\dmd2\\\\windows\\\\bin\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\base64.d\" ascii wide"}

{"name":"$dlang5","value":"\"C:\\\\D\\\\dmd2\\\\windows\\\\bin\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\stdio.d\" ascii wide"}

{"name":"$dlang6","value":"\"\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\utf.d\" ascii wide"}

{"name":"$dlang7","value":"\"\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\file.d\" ascii wide"}

{"name":"$dlang8","value":"\"\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\format.d\" ascii wide"}

{"name":"$dlang9","value":"\"\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\base64.d\" ascii wide"}

{"name":"$dlang10","value":"\"\\\\..\\\\..\\\\src\\\\phobos\\\\std\\\\stdio.d\" ascii wide"}

{"name":"$dlang11","value":"\"Unexpected '\\\\n' when converting from type const(char)[] to type int\" ascii wide"}

{"name":"$ign1","value":"\"--strip-comments\""}

{"name":"$ign2","value":"\"Usage: rdmd [RDMD AND DMD OPTIONS]\""}

{"name":"$s1","value":"\"CloseHandle\""}

{"name":"$s2","value":"\"CommandLineToArgvW\""}

{"name":"$s3","value":"\"CreateFileA\""}

{"name":"$s4","value":"\"CreateSemaphoreA\""}

{"name":"$s5","value":"\"CreateThread\""}

{"name":"$s6","value":"\"DeleteCriticalSection\""}

{"name":"$s7","value":"\"DeleteFileA\""}

{"name":"$s8","value":"\"DuplicateHandle\""}

{"name":"$s9","value":"\"EnterCriticalSection\""}

{"name":"$s10","value":"\"ExitProcess\""}

{"name":"$s11","value":"\"ExitThread\""}

{"name":"$s12","value":"\"ExpandEnvironmentStringsW\""}

{"name":"$s13","value":"\"FileTimeToDosDateTime\""}

{"name":"$s14","value":"\"FindClose\""}

{"name":"$s15","value":"\"FindFirstFileA\""}

{"name":"$s16","value":"\"FindFirstFileW\""}

{"name":"$s17","value":"\"FindNextFileA\""}

{"name":"$s18","value":"\"FindNextFileW\""}

{"name":"$s19","value":"\"FormatMessageW\""}

{"name":"$s20","value":"\"FreeEnvironmentStringsA\""}

{"name":"$s21","value":"\"FreeEnvironmentStringsW\""}

{"name":"$s22","value":"\"FreeLibrary\""}

{"name":"$s23","value":"\"GetACP\""}

{"name":"$s24","value":"\"GetCPInfo\""}

{"name":"$s25","value":"\"GetCommandLineA\""}

{"name":"$s26","value":"\"GetCommandLineW\""}

{"name":"$s27","value":"\"GetConsoleOutputCP\""}

{"name":"$s28","value":"\"GetConsoleScreenBufferInfo\""}

{"name":"$s29","value":"\"GetCurrentProcess\""}

{"name":"$s30","value":"\"GetCurrentThread\""}

{"name":"$s31","value":"\"GetCurrentThreadId\""}

{"name":"$s32","value":"\"GetEnvironmentStrings\""}

{"name":"$s33","value":"\"GetEnvironmentStringsW\""}

{"name":"$s34","value":"\"GetEnvironmentVariableA\""}

{"name":"$s35","value":"\"GetEnvironmentVariableW\""}

{"name":"$s36","value":"\"GetExitCodeThread\""}

{"name":"$s37","value":"\"GetFileAttributesW\""}

{"name":"$s38","value":"\"GetFileType\""}

{"name":"$s39","value":"\"GetLastError\""}

{"name":"$s40","value":"\"GetModuleFileNameA\""}

{"name":"$s41","value":"\"GetModuleHandleA\""}

{"name":"$s42","value":"\"GetOEMCP\""}

{"name":"$s43","value":"\"GetProcAddress\""}

{"name":"$s44","value":"\"GetProcessHeap\""}

{"name":"$s45","value":"\"GetStdHandle\""}

{"name":"$s46","value":"\"GetStringTypeA\""}

{"name":"$s47","value":"\"GetSystemInfo\""}

{"name":"$s48","value":"\"GetThreadContext\""}

{"name":"$s49","value":"\"GetTickCount\""}

{"name":"$s50","value":"\"GetTimeZoneInformation\""}

{"name":"$s51","value":"\"GetVersion\""}

{"name":"$s52","value":"\"GlobalAlloc\""}

{"name":"$s53","value":"\"GlobalFree\""}

{"name":"$s54","value":"\"GlobalMemoryStatus\""}

{"name":"$s55","value":"\"HeapAlloc\""}

{"name":"$s56","value":"\"HeapFree\""}

{"name":"$s57","value":"\"HeapReAlloc\""}

{"name":"$s58","value":"\"InitializeCriticalSection\""}

{"name":"$s59","value":"\"IsDebuggerPresent\""}

{"name":"$s60","value":"\"LCMapStringA\""}

{"name":"$s61","value":"\"LeaveCriticalSection\""}

{"name":"$s62","value":"\"LoadLibraryA\""}

{"name":"$s63","value":"\"LoadLibraryW\""}

{"name":"$s64","value":"\"LocalFree\""}

{"name":"$s65","value":"\"MessageBoxA\""}

{"name":"$s66","value":"\"MultiByteToWideChar\""}

{"name":"$s67","value":"\"QueryPerformanceCounter\""}

{"name":"$s68","value":"\"QueryPerformanceFrequency\""}

{"name":"$s69","value":"\"RaiseException\""}

{"name":"$s70","value":"\"ReadFile\""}

{"name":"$s71","value":"\"RegCloseKey\""}

{"name":"$s72","value":"\"RegCreateKeyExW\""}

{"name":"$s73","value":"\"RegDeleteKeyW\""}

{"name":"$s74","value":"\"RegDeleteValueW\""}

{"name":"$s75","value":"\"RegEnumKeyExW\""}

{"name":"$s76","value":"\"RegEnumValueW\""}

{"name":"$s77","value":"\"RegFlushKey\""}

{"name":"$s78","value":"\"RegOpenKeyExW\""}

{"name":"$s79","value":"\"RegOpenKeyW\""}

{"name":"$s80","value":"\"RegQueryInfoKeyW\""}

{"name":"$s81","value":"\"RegQueryValueExW\""}

{"name":"$s82","value":"\"RegSetValueExW\""}

{"name":"$s83","value":"\"ReleaseSemaphore\""}

{"name":"$s84","value":"\"ResumeThread\""}

{"name":"$s85","value":"\"RtlCaptureContext\""}

{"name":"$s86","value":"\"RtlUnwind\""}

{"name":"$s87","value":"\"SetConsoleCtrlHandler\""}

{"name":"$s88","value":"\"SetEnvironmentVariableW\""}

{"name":"$s89","value":"\"SetFilePointer\""}

{"name":"$s90","value":"\"SetHandleCount\""}

{"name":"$s91","value":"\"SetLastError\""}

{"name":"$s92","value":"\"Sleep\""}

{"name":"$s93","value":"\"SuspendThread\""}

{"name":"$s94","value":"\"SwitchToThread\""}

{"name":"$s95","value":"\"SystemTimeToTzSpecificLocalTime\""}

{"name":"$s96","value":"\"TryEnterCriticalSection\""}

{"name":"$s97","value":"\"TzSpecificLocalTimeToSystemTime\""}

{"name":"$s98","value":"\"UnhandledExceptionFilter\""}

{"name":"$s99","value":"\"VirtualAlloc\""}

{"name":"$s100","value":"\"VirtualFree\""}

{"name":"$s101","value":"\"WaitForSingleObject\""}

{"name":"$s102","value":"\"WideCharToMultiByte\""}

{"name":"$s103","value":"\"WriteConsoleA\""}

{"name":"$s104","value":"\"WriteFile\""}

{"name":"$s105","value":"\"lstrlenW\""}

Threat Analysis

This YARA rule is designed to detect general threats.

Severity Level: High

The rule uses pattern matching to identify specific byte sequences, strings, or behavioral patterns associated with malicious activity.

Detection Capabilities

File-based detection for executables and documents
Memory scanning for running processes
Network traffic analysis support

Command Line Usage

# Scan a single file
yara APT_Backdoor_Win_DShell_2.yar /path/to/suspicious/file

# Scan a directory recursively
yara -r APT_Backdoor_Win_DShell_2.yar /path/to/directory/

# Scan with metadata output
yara -m APT_Backdoor_Win_DShell_2.yar target_file

# Scan process memory (Linux)
yara APT_Backdoor_Win_DShell_2.yar /proc/[pid]/exe

Integration Examples

Python (yara-python)

import yara
rules = yara.compile(filepath='APT_Backdoor_Win_DShell_2.yar')
matches = rules.match('/path/to/file')

ClamAV Integration

clamscan --yara-rules=APT_Backdoor_Win_DShell_2.yar /path/to/scan

Rule Information

YARA ID

YARA-2025-1077

Author

Unknown

Repository

fireeye_red_team_tool_countermeasures

Created

August 19, 2025

Last Updated

August 19, 2025

Last Imported

Never

Threat Intelligence

Risk Level High

Category general

Detection Confidence Analysis Pending

False Positive Rate Not Available

Last Seen in Wild No Data

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Export Options

Similar Rules in general

YARA-2023-0001 CRI

APT_Backdoor_Win_DShell_2

String Definitions

Threat Analysis

Detection Capabilities

Command Line Usage

Integration Examples

Python (yara-python)

ClamAV Integration

Rule Information

Threat Intelligence

Related Rules

Export Options

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