analyzing-indicators-of-compromise

Analyzing Indicators Of Compromise

Overview

Cybersecurity skill for analyzing indicators of compromise. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "analyzing indicators of compromise"
• "A phishing email or alert generates IOCs (URLs, IP addresses, file hashes) requi"
• "Automated feeds deliver bulk IOCs that need confidence scoring before ingestion"
• "An incident investigation requires contextual enrichment of observed network art"

Use this skill when:

• A phishing email or alert generates IOCs (URLs, IP addresses, file hashes) requiring rapid triage
• Automated feeds deliver bulk IOCs that need confidence scoring before ingestion into blocking controls
• An incident investigation requires contextual enrichment of observed network artifacts

Do not use this skill in isolation for high-stakes blocking decisions — always combine automated enrichment with analyst judgment, especially for shared infrastructure (CDNs, cloud providers).

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

• VirusTotal API key (free or Enterprise) for multi-AV and sandbox lookup
• AbuseIPDB API key for IP reputation checks
• MISP instance or TIP for cross-referencing against known campaigns
• Python with requests and vt-py libraries, or SOAR platform with pre-built connectors

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: str) -> dict:
    return {k: re.findall(v, text) for k, v in IOC_PATTERNS.items()}

1. Scope the Analysis — Define what indicators of compromise artifacts or data sources to examine and the investigation timeline.
2. Preserve Evidence — Create forensic copies of relevant data. Maintain chain of custody documentation.
3. Extract Key Indicators — Parse and extract relevant indicators of compromise data points from collected artifacts.
4. Correlate Findings — Cross-reference extracted data with other sources (threat intel, logs, timelines).
5. Build Timeline — Construct a chronological sequence of events related to indicators of compromise.
6. Document Analysis — Write findings report with evidence, conclusions, and recommendations.