Imported from oyi77/1ai-skills (cybersecurity/_deprecated/hunting-for-living-off-the-land-binaries/SKILL.md). Install upstream with npx skills add oyi77/1ai-skills --skill hunting-for-living-off-the-land-binaries. Copyright stays with the author (Apache-2.0).

Hunting For Living Off The Land Binaries

Overview

Cybersecurity skill for hunting for living off the land binaries. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "hunting for living off the land binaries"

• "Proactively hunt for adversary abuse of legitimate system binaries (LOLBins) to "

• When investigating fileless malware campaigns that bypass traditional AV

• During proactive threat hunts targeting defense evasion techniques

• When EDR alerts fire on legitimate binaries executing unusual child processes

• After threat intelligence reports indicate LOLBin abuse in active campaigns

• During red team/purple team exercises validating detection coverage for T1218

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

• Access to EDR telemetry (CrowdStrike, Microsoft Defender for Endpoint, SentinelOne)
• SIEM with process creation logs (Sysmon Event ID 1, Windows Security 4688)
• Familiarity with LOLBAS Project (lolbas-project.github.io) reference list
• PowerShell command-line logging enabled (Module Logging, Script Block Logging)
• Network proxy or firewall logs for correlating outbound connections

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 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 .
3. Build Detection Queries — Write living off the land binaries queries targeting indicators. Use platform-specific query language for optimal performance.
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

• living off the land binaries — Primary tool for this skill
• 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 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