hunting-for-dcsync-attacks

Detect DCSync attacks by analyzing Windows Event ID 4662 for unauthorized DS-Replication-Get-Changes requests from non-domain-controller accounts.

16 stars

byplurigrid

View on GitHub Installation ↓

Best use case

hunting-for-dcsync-attacks is best used when you need a repeatable AI agent workflow instead of a one-off prompt.

Detect DCSync attacks by analyzing Windows Event ID 4662 for unauthorized DS-Replication-Get-Changes requests from non-domain-controller accounts.

Teams using hunting-for-dcsync-attacks should expect a more consistent output, faster repeated execution, less prompt rewriting.

When to use this skill

You want a reusable workflow that can be run more than once with consistent structure.

When not to use this skill

You only need a quick one-off answer and do not need a reusable workflow.
You cannot install or maintain the underlying files, dependencies, or repository context.

Installation

Claude Code / Cursor / Codex

$curl -o ~/.claude/skills/hunting-for-dcsync-attacks/SKILL.md --create-dirs "https://raw.githubusercontent.com/plurigrid/asi/main/plugins/asi/skills/hunting-for-dcsync-attacks/SKILL.md"

Manual Installation

Download SKILL.md from GitHub
Place it in .claude/skills/hunting-for-dcsync-attacks/SKILL.md inside your project
Restart your AI agent — it will auto-discover the skill

How hunting-for-dcsync-attacks Compares

Feature / Agent	hunting-for-dcsync-attacks	Standard Approach
Platform Support	Not specified	Limited / Varies
Context Awareness	High	Baseline
Installation Complexity	Unknown	N/A

Frequently Asked Questions

What does this skill do?

Detect DCSync attacks by analyzing Windows Event ID 4662 for unauthorized DS-Replication-Get-Changes requests from non-domain-controller accounts.

Where can I find the source code?

You can find the source code on GitHub using the link provided at the top of the page.

SKILL.md Source

# Hunting for DCSync Attacks

## When to Use

- 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

## 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

1. **Enable Auditing**: Ensure Audit Directory Service Access is enabled on domain controllers.
2. **Collect Events**: Gather Windows Event ID 4662 with AccessMask 0x100 (Control Access).
3. **Filter Replication GUIDs**: Search for DS-Replication-Get-Changes and DS-Replication-Get-Changes-All.
4. **Identify Non-DC Sources**: Flag events where SubjectUserName is not a domain controller machine account.
5. **Correlate with Network**: Cross-reference source IPs against known DC addresses.
6. **Validate Findings**: Exclude legitimate replication tools (Azure AD Connect, SCCM).
7. **Respond**: Disable compromised accounts, reset krbtgt, investigate lateral movement.

## Key Concepts

| Concept | Description |
|---------|-------------|
| DCSync | Technique abusing AD replication protocol to extract password hashes |
| Event ID 4662 | Directory Service Access audit event |
| DS-Replication-Get-Changes | GUID 1131f6aa-9c07-11d1-f79f-00c04fc2dcd2 |
| DS-Replication-Get-Changes-All | GUID 1131f6ad-9c07-11d1-f79f-00c04fc2dcd2 |
| AccessMask 0x100 | Control Access right indicating extended rights verification |
| T1003.006 | OS Credential Dumping: DCSync |

## Tools & Systems

| Tool | Purpose |
|------|---------|
| Windows Event Viewer | Direct event log analysis |
| Splunk | SIEM correlation of Event 4662 |
| Elastic Security | Detection rules for DCSync patterns |
| Mimikatz lsadump::dcsync | Attack tool used to perform DCSync |
| Impacket secretsdump.py | Python-based DCSync implementation |
| BloodHound | Identify accounts with replication rights |

## Output Format

```
Hunt ID: TH-DCSYNC-[DATE]-[SEQ]
Technique: T1003.006
Domain Controller: [DC hostname]
Subject Account: [Account performing replication]
Source IP: [Non-DC IP address]
GUID Accessed: [Replication GUID]
Risk Level: [Critical/High/Medium/Low]
Recommended Action: [Disable account, reset krbtgt, investigate]
```

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