UNC2891_Steelcorgi

YARA-2024-0173 Medium general Active

Detects UNC2891 Steelcorgi packed ELF binaries

UNC2891_Steelcorgi.yar Valid Syntax
rule UNC2891_Steelcorgi
{
	meta:
		description = "Detects UNC2891 Steelcorgi packed ELF binaries"
		author = "Frank Boldewin (@r3c0nst)"
		date = "2022-30-03"
		hash1 = "0760cd30d18517e87bf9fd8555513423db1cd80730b47f57167219ddbf91f170"
		hash2 = "3560ed07aac67f73ef910d0b928db3c0bb5f106b5daee054666638b6575a89c5"
		hash3 = "5b4bb50055b31dbd897172583c7046dd27cd03e1e3d84f7a23837e8df7943547"
		
	strings:
		$pattern1 = {70 61 64 00 6C 63 6B 00} // padlck
		$pattern2 = {FF 72 FF 6F FF 63 FF 2F FF 73 FF 65 FF 6C FF 66 FF 2F FF 65 FF 78 FF 65} // proc_self_exe
		
	condition:
		uint32(0) == 0x464c457f and all of them
}

Rule Metadata

description
Detects UNC2891 Steelcorgi packed ELF binaries
author
Frank Boldewin (@r3c0nst)
date
2022-30-03
hash1
0760cd30d18517e87bf9fd8555513423db1cd80730b47f57167219ddbf91f170
hash2
3560ed07aac67f73ef910d0b928db3c0bb5f106b5daee054666638b6575a89c5
hash3
5b4bb50055b31dbd897172583c7046dd27cd03e1e3d84f7a23837e8df7943547

String Definitions

{"name":"$pattern1","value":"{70 61 64 00 6C 63 6B 00} \/\/ padlck"}
{"name":"$pattern2","value":"{FF 72 FF 6F FF 63 FF 2F FF 73 FF 65 FF 6C FF 66 FF 2F FF 65 FF 78 FF 65} \/\/ proc_self_exe"}

Threat Analysis

This YARA rule is designed to detect general threats.

Severity Level: Medium

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 UNC2891_Steelcorgi.yar /path/to/suspicious/file

# Scan a directory recursively
yara -r UNC2891_Steelcorgi.yar /path/to/directory/

# Scan with metadata output
yara -m UNC2891_Steelcorgi.yar target_file

# Scan process memory (Linux)
yara UNC2891_Steelcorgi.yar /proc/[pid]/exe

Integration Examples

Python (yara-python)

import yara
rules = yara.compile(filepath='UNC2891_Steelcorgi.yar')
matches = rules.match('/path/to/file')

ClamAV Integration

clamscan --yara-rules=UNC2891_Steelcorgi.yar /path/to/scan

Rule Information

YARA ID
YARA-2024-0173
Created
August 19, 2025
Last Updated
August 19, 2025
Last Imported
Never

Threat Intelligence

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

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