performing-malware-triage-with-yara

name	performing-malware-triage-with-yara
description	Use when performing rapid malware triage and classification using YARA rules to match file patterns, strings, byte sequences, and structural characteristics against known malware families and suspicious indicators. Covers rule writing, scanning, and integration with analysis pipelines. Activates for requests involving YARA rule creation, malware classification, pattern matching, sample triage, or signature-based detection.
domain	cybersecurity
tags	["malware","YARA","triage","classification","pattern-matching"]
subdomain	malware-analysis
version	1.0.0
author	oyi77
license	Apache-2.0
nist_csf	["DE.AE-02","RS.AN-03","ID.RA-01","DE.CM-01"]

Performing Malware Triage With Yara

Overview

Cybersecurity skill for performing malware triage with yara. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "performing malware triage with yara"

• "Performs rapid malware triage and classification using YARA rules to match file "

• Rapidly classifying a large batch of malware samples against known family signatures

• Writing detection rules for a newly analyzed malware family based on unique byte patterns

• Scanning file shares, endpoints, or memory dumps for indicators of a specific threat

• Building automated triage pipelines that classify samples before manual analysis

• Hunting for variants of a known threat across an enterprise using YARA scans

Do not use as the sole analysis method; YARA triage identifies known patterns but does not reveal new or unknown malware behaviors.

When NOT to Use

• When you lack proper authorization for testing
• For production systems without change management
• When the task requires legal or compliance expertise beyond technical scope

Prerequisites

• YARA 4.x installed (apt install yara or pip install yara-python)
• YARA rule repositories (YARA-Rules, awesome-yara, Malpedia rules, Florian Roth's signature-base)
• Python 3.8+ with yara-python for scripted scanning
• Sample collection organized in a directory structure for batch scanning
• Understanding of PE file format, hex patterns, and regular expressions for rule writing

Workflow

# Example: IOC detection
import re

IOC_PATTERNS = {
    "ip": r"\b(?:\d{1,3}\.){3}\d{1,3}\b",
    "domain": r"\b[a-z0-9-]+\.[a-z]{2,}\b",
    "hash_md5": r"\b[a-f0-9]{32}\b",
    "hash_sha256": r"\b[a-f0-9]{64}\b",
}

def extract_iocs(text: ) -> :
     {k: re.findall(v, text)  k, v  IOC_PATTERNS.items()}