Hunting For Dcsync Attacks

Hunting For Dcsync Attacks

Overview

Cybersecurity skill for hunting for dcsync attacks. Follows industry best practices and security standards.

When to Use

Trigger phrases:

• "hunting for dcsync attacks"

• "Detect DCSync attacks by analyzing Windows Event ID 4662 for unauthorized DS-Rep"

• When hunting for DCSync credential theft (MITRE ATT&CK T1003.006)

• After detecting Mimikatz or similar tools in the environment

• During incident response involving Active Directory compromise

• When monitoring for unauthorized domain replication requests

• During purple team exercises testing AD attack detection

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

• Windows Security Event Log forwarding enabled (Event ID 4662)
• Audit Directory Service Access enabled via Group Policy
• Domain Computers SACL configured on Domain Object for machine account detection
• SIEM with Windows event data ingested (Splunk, Elastic, Sentinel)
• Knowledge of legitimate domain controller accounts and replication partners

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 dcsync attacks 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

• dcsync attacks — 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