Ransomware_Win_DARKSIDE_v1__1

YARA-2025-1175 Critical general Active

Detection for early versions of DARKSIDE ransomware samples based on the encryption mode configuration values

Ransomware_Win_DARKSIDE_v1__1.yar Valid Syntax
rule Ransomware_Win_DARKSIDE_v1__1
{
    meta:
        author = "FireEye"
        reference = "https://www.mandiant.com/resources/shining-a-light-on-darkside-ransomware-operations"
        date_created = "2021-03-22"
        description = "Detection for early versions of DARKSIDE ransomware samples based on the encryption mode configuration values"
		md5 = "1a700f845849e573ab3148daef1a3b0b"
    strings:
		$consts = { 80 3D [4] 01 [1-10] 03 00 00 00 [1-10] 03 00 00 00 [1-10] 00 00 04 00 [1-10] 00 00 00 00 [1-30] 80 3D [4] 02 [1-10] 03 00 00 00 [1-10] 03 00 00 00 [1-10] FF FF FF FF [1-10] FF FF FF FF [1-30] 03 00 00 00 [1-10] 03 00 00 00 }
	condition:
        (uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and $consts
}

Rule Metadata

author
FireEye
reference
https://www.mandiant.com/resources/shining-a-light-on-darkside-ransomware-operations
date_created
2021-03-22
description
Detection for early versions of DARKSIDE ransomware samples based on the encryption mode configuration values
md5
1a700f845849e573ab3148daef1a3b0b

String Definitions

{"name":"$consts","value":"{ 80 3D [4] 01 [1-10] 03 00 00 00 [1-10] 03 00 00 00 [1-10] 00 00 04 00 [1-10] 00 00 00 00 [1-30] 80 3D [4] 02 [1-10] 03 00 00 00 [1-10] 03 00 00 00 [1-10] FF FF FF FF [1-10] FF FF FF FF [1-30] 03 00 00 00 [1-10] 03 00 00 00 }"}

Threat Analysis

This YARA rule is designed to detect general threats.

Severity Level: Critical

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 Ransomware_Win_DARKSIDE_v1__1.yar /path/to/suspicious/file

# Scan a directory recursively
yara -r Ransomware_Win_DARKSIDE_v1__1.yar /path/to/directory/

# Scan with metadata output
yara -m Ransomware_Win_DARKSIDE_v1__1.yar target_file

# Scan process memory (Linux)
yara Ransomware_Win_DARKSIDE_v1__1.yar /proc/[pid]/exe

Integration Examples

Python (yara-python)

import yara
rules = yara.compile(filepath='Ransomware_Win_DARKSIDE_v1__1.yar')
matches = rules.match('/path/to/file')

ClamAV Integration

clamscan --yara-rules=Ransomware_Win_DARKSIDE_v1__1.yar /path/to/scan

Rule Information

YARA ID
YARA-2025-1175
Author
Created
August 19, 2025
Last Updated
August 19, 2025
Last Imported
Never

Threat Intelligence

Risk Level Critical
Category general
Detection Confidence Analysis Pending
False Positive Rate Not Available
Last Seen in Wild No Data

Export Options