Hunting Advanced Persistent Threats

Hunting Advanced Persistent Threats

Overview

Cybersecurity skill for hunting advanced persistent threats. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "hunting advanced persistent threats"
• "Conducting proactive threat hunting sprints (typically 2–4 week cycles) based on"
• "A UEBA alert or anomaly detection system flags behavioral deviations warranting"
• "A peer organization or ISAC sharing partner reports active APT compromise and yo"

Use this skill when:

• Conducting proactive threat hunting sprints (typically 2–4 week cycles) based on newly published APT intelligence
• A UEBA alert or anomaly detection system flags behavioral deviations warranting deeper investigation
• A peer organization or ISAC sharing partner reports active APT compromise and you need to validate your own exposure

Do not use this skill as a substitute for incident response when a confirmed breach is in progress — escalate to IR procedures (NIST SP 800-61).

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

• EDR platform with telemetry retention (CrowdStrike Falcon, Microsoft Defender for Endpoint, or SentinelOne) covering 30+ days
• Access to MITRE ATT&CK Navigator for hypothesis development
• Network flow data (NetFlow, Zeek, or Suricata logs) in a queryable SIEM
• Threat hunting platform or query interface (Velociraptor, osquery fleet, or Splunk ES)

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. Define Detection Scope — Identify the specific advanced persistent threats techniques or indicators to hunt. Map to MITRE ATT&CK tactics/techniques where applicable.
2. Collect Baseline Data — Gather historical logs and establish normal behavior patterns for advanced persistent threats.
3. Build Detection Queries — Write detection rules, Sigma rules, or SIEM queries targeting advanced persistent threats indicators.
4. Execute Hunts — Run queries against the collected data, starting with broad filters and narrowing down.
5. Triage Results — Investigate alerts, filter false positives, and validate findings against known-good behavior.
6. Document Findings — Record confirmed detections, IOCs, and affected systems. Update detection rules based on findings.

Tools

• SIEM Platform — Central log aggregation and query execution
• Sigma Rules — Vendor-agnostic detection rule format
• MITRE ATT&CK Navigator — Technique mapping and coverage analysis

Process

1. Reconnaissance — Gather target information, identify attack surface, enumerate services
2. Analysis/Exploitation — Execute the technique, analyze results, document findings
3. Reporting — Document IOCs, write findings, provide remediation recommendations

Verification

• All advanced persistent threats procedures executed completely and documented
• Findings validated against multiple data sources
• False positives identified and filtered
• Results documented with evidence and timestamps
• Recommendations provided with risk-based prioritization

Anti-Rationalization Table