APT_Backdoor_Win_DShell_3

YARA-2025-1020 High general Active

No description available for this rule

APT_Backdoor_Win_DShell_3.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_3
{
    meta:
        description = "This rule looks for strings specific to the D programming language in combination with sections of an integer array which contains the encoded payload found within DShell"
        md5 = "cf752e9cd2eccbda5b8e4c29ab5554b6"
        rev = 3
        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
        $e0 = ",0,"
        $e1 = ",1,"
        $e2 = ",2,"
        $e3 = ",3,"
        $e4 = ",4,"
        $e5 = ",5,"
        $e6 = ",6,"
        $e7 = ",7,"
        $e8 = ",8,"
        $e9 = ",9,"
        $e10 = ",10,"
        $e11 = ",11,"
        $e12 = ",12,"
        $e13 = ",13,"
        $e14 = ",14,"
        $e15 = ",15,"
        $e16 = ",16,"
        $e17 = ",17,"
        $e18 = ",18,"
        $e19 = ",19,"
        $e20 = ",20,"
        $e21 = ",21,"
        $e22 = ",22,"
        $e23 = ",23,"
        $e24 = ",24,"
        $e25 = ",25,"
        $e26 = ",26,"
        $e27 = ",27,"
        $e28 = ",28,"
        $e29 = ",29,"
        $e30 = ",30,"
        $e31 = ",31,"
        $e32 = ",32,"
        $e33 = ",33,"
        $e34 = ",34,"
        $e35 = ",35,"
        $e36 = ",36,"
        $e37 = ",37,"
        $e38 = ",38,"
        $e39 = ",39,"
        $e40 = ",40,"
        $e41 = ",41,"
        $e42 = ",42,"
        $e43 = ",43,"
        $e44 = ",44,"
        $e45 = ",45,"
        $e46 = ",46,"
        $e47 = ",47,"
        $e48 = ",48,"
        $e49 = ",49,"
        $e50 = ",50,"
        $e51 = ",51,"
        $e52 = ",52,"
        $e53 = ",53,"
        $e54 = ",54,"
        $e55 = ",55,"
        $e56 = ",56,"
        $e57 = ",57,"
        $e58 = ",58,"
        $e59 = ",59,"
        $e60 = ",60,"
        $e61 = ",61,"
        $e62 = ",62,"
        $e63 = ",63,"
        $e64 = ",64,"
    condition:
        (uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and filesize > 500KB and filesize < 1500KB and 40 of ($e*) and 1 of ($dlang*)
}

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":"$e0","value":"\",0,\""}

{"name":"$e1","value":"\",1,\""}

{"name":"$e2","value":"\",2,\""}

{"name":"$e3","value":"\",3,\""}

{"name":"$e4","value":"\",4,\""}

{"name":"$e5","value":"\",5,\""}

{"name":"$e6","value":"\",6,\""}

{"name":"$e7","value":"\",7,\""}

{"name":"$e8","value":"\",8,\""}

{"name":"$e9","value":"\",9,\""}

{"name":"$e10","value":"\",10,\""}

{"name":"$e11","value":"\",11,\""}

{"name":"$e12","value":"\",12,\""}

{"name":"$e13","value":"\",13,\""}

{"name":"$e14","value":"\",14,\""}

{"name":"$e15","value":"\",15,\""}

{"name":"$e16","value":"\",16,\""}

{"name":"$e17","value":"\",17,\""}

{"name":"$e18","value":"\",18,\""}

{"name":"$e19","value":"\",19,\""}

{"name":"$e20","value":"\",20,\""}

{"name":"$e21","value":"\",21,\""}

{"name":"$e22","value":"\",22,\""}

{"name":"$e23","value":"\",23,\""}

{"name":"$e24","value":"\",24,\""}

{"name":"$e25","value":"\",25,\""}

{"name":"$e26","value":"\",26,\""}

{"name":"$e27","value":"\",27,\""}

{"name":"$e28","value":"\",28,\""}

{"name":"$e29","value":"\",29,\""}

{"name":"$e30","value":"\",30,\""}

{"name":"$e31","value":"\",31,\""}

{"name":"$e32","value":"\",32,\""}

{"name":"$e33","value":"\",33,\""}

{"name":"$e34","value":"\",34,\""}

{"name":"$e35","value":"\",35,\""}

{"name":"$e36","value":"\",36,\""}

{"name":"$e37","value":"\",37,\""}

{"name":"$e38","value":"\",38,\""}

{"name":"$e39","value":"\",39,\""}

{"name":"$e40","value":"\",40,\""}

{"name":"$e41","value":"\",41,\""}

{"name":"$e42","value":"\",42,\""}

{"name":"$e43","value":"\",43,\""}

{"name":"$e44","value":"\",44,\""}

{"name":"$e45","value":"\",45,\""}

{"name":"$e46","value":"\",46,\""}

{"name":"$e47","value":"\",47,\""}

{"name":"$e48","value":"\",48,\""}

{"name":"$e49","value":"\",49,\""}

{"name":"$e50","value":"\",50,\""}

{"name":"$e51","value":"\",51,\""}

{"name":"$e52","value":"\",52,\""}

{"name":"$e53","value":"\",53,\""}

{"name":"$e54","value":"\",54,\""}

{"name":"$e55","value":"\",55,\""}

{"name":"$e56","value":"\",56,\""}

{"name":"$e57","value":"\",57,\""}

{"name":"$e58","value":"\",58,\""}

{"name":"$e59","value":"\",59,\""}

{"name":"$e60","value":"\",60,\""}

{"name":"$e61","value":"\",61,\""}

{"name":"$e62","value":"\",62,\""}

{"name":"$e63","value":"\",63,\""}

{"name":"$e64","value":"\",64,\""}

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_3.yar /path/to/suspicious/file

# Scan a directory recursively
yara -r APT_Backdoor_Win_DShell_3.yar /path/to/directory/

# Scan with metadata output
yara -m APT_Backdoor_Win_DShell_3.yar target_file

# Scan process memory (Linux)
yara APT_Backdoor_Win_DShell_3.yar /proc/[pid]/exe

Integration Examples

Python (yara-python)

import yara
rules = yara.compile(filepath='APT_Backdoor_Win_DShell_3.yar')
matches = rules.match('/path/to/file')

ClamAV Integration

clamscan --yara-rules=APT_Backdoor_Win_DShell_3.yar /path/to/scan

Rule Information

YARA ID

YARA-2025-1020

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

Related Rules

APT_HackTool_MSIL_TITOSPECIAL_1

YARA-2025-0921

Medium

HackTool_MSIL_INVEIGHZERO_1

YARA-2025-0922

Medium

HackTool_MSIL_CoreHound_1

YARA-2025-0923

Medium

APT_Dropper_Win64_MATRYOSHKA_1

YARA-2025-0924

Medium

Tool_MSIL_CSharpUtils_1

YARA-2025-0925

Medium

Export Options

Similar Rules in general

YARA-2023-0001 CRI

APT_Backdoor_Win_DShell_3

String Definitions

Threat Analysis

Detection Capabilities

Command Line Usage

Integration Examples

Python (yara-python)

ClamAV Integration

Rule Information

Threat Intelligence

Related Rules

Export Options

Similar Rules in general

Detect_Mimic_Ransomware

SystemBC_malware

detect_catB

detect_Typhon_Stealer

Nosu_stealer

detect_Lumma_stealer

detect_StrelaStealer

detect_silence_Downloader