aPLib_decompression

YARA-2022-0211 Medium general Active

Detects aPLib decompression code often used in malware

aPLib_decompression.yar Valid Syntax
rule aPLib_decompression
{     
	meta:
		description = "Detects aPLib decompression code often used in malware"
		author="@r3c0nst"
		date="2021-24-03"
		reference="https://ibsensoftware.com/files/aPLib-1.1.1.zip"

	strings:
		$pattern1 = { FC B2 80 31 DB A4 B3 02 }
		$pattern2 = { AC D1 E8 74 ?? 11 C9 EB }
		$pattern3 = { 73 0A 80 FC 05 73 ?? 83 F8 7F 77 }

	condition:
		filesize < 10MB and all of them
}

Rule Metadata

description
Detects aPLib decompression code often used in malware
author
@r3c0nst
date
2021-24-03
reference
https://ibsensoftware.com/files/aPLib-1.1.1.zip

String Definitions

{"name":"$pattern1","value":"{ FC B2 80 31 DB A4 B3 02 }"}
{"name":"$pattern2","value":"{ AC D1 E8 74 ?? 11 C9 EB }"}
{"name":"$pattern3","value":"{ 73 0A 80 FC 05 73 ?? 83 F8 7F 77 }"}

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 aPLib_decompression.yar /path/to/suspicious/file

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

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

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

Integration Examples

Python (yara-python)

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

ClamAV Integration

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

Rule Information

YARA ID
YARA-2022-0211
Author
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

Export Options