hunting-for-dcsync-attacks

name	hunting-for-dcsync-attacks
description	Detect DCSync attacks by analyzing Windows Event ID 4662 for unauthorized DS-Replication-Get-Changes requests from non-domain-controller accounts. Use when detecting dcsync attacks by analyzing windows event id 4662 for.
domain	cybersecurity
tags	["threat-hunting","dcsync","active-directory","credential-access","t1003.006","mimikatz","windows","dfir"]
subdomain	threat-hunting
version	1.0
author	oyi77
license	Apache-2.0
d3fend_techniques	["Application Protocol Command Analysis","Network Isolation","Network Traffic Analysis","Client-server Payload Profiling","Platform Monitoring"]
nist_csf	["DE.CM-01","DE.AE-02","DE.AE-07","ID.RA-05"]

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.