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Anthropic-Cybersecurity-Skills/skills/detecting-kerberoasting-attacks/SKILL.md
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Mahipal 2fb6a9faff Rewrite 548 skill descriptions to the activation rubric
Each rewritten description now states both what the skill does (concrete
capability, named tools/artifacts) and an explicit when-to-use trigger,
improving agent discovery/activation. Grounded in each skill's own body;
changes confined to the `description` field only (bodies and all other
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Schema: 817/817 pass. Framework-ID gate: 0 defects.
2026-08-02 09:32:13 -07:00

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---
name: detecting-kerberoasting-attacks
description: Detect Kerberoasting attacks by monitoring for anomalous Kerberos TGS
requests (Event ID 4769) targeting service accounts with SPNs, which attackers request
offline to crack service account passwords. Use when hunting for MITRE T1558 credential
access activity or investigating suspected service account password cracking attempts
in Active Directory Kerberos logs.
domain: cybersecurity
subdomain: threat-hunting
tags:
- threat-hunting
- mitre-attack
- kerberoasting
- credential-access
- kerberos
- t1558
- proactive-detection
version: '1.0'
author: mahipal
license: Apache-2.0
d3fend_techniques:
- Application Protocol Command Analysis
- Network Isolation
- Network Traffic Analysis
- Client-server Payload Profiling
- Network Traffic Community Deviation
nist_csf:
- DE.CM-01
- DE.AE-02
- DE.AE-07
- ID.RA-05
mitre_attack:
- T1046
- T1057
- T1082
- T1083
- T1003
---
# Detecting Kerberoasting Attacks
## When to Use
- When proactively hunting for indicators of detecting kerberoasting attacks in the environment
- After threat intelligence indicates active campaigns using these techniques
- During incident response to scope compromise related to these techniques
- When EDR or SIEM alerts trigger on related indicators
- During periodic security assessments and purple team exercises
## Prerequisites
- EDR platform with process and network telemetry (CrowdStrike, MDE, SentinelOne)
- SIEM with relevant log data ingested (Splunk, Elastic, Sentinel)
- Sysmon deployed with comprehensive configuration
- Windows Security Event Log forwarding enabled
- Threat intelligence feeds for IOC correlation
## Workflow
1. **Formulate Hypothesis**: Define a testable hypothesis based on threat intelligence or ATT&CK gap analysis.
2. **Identify Data Sources**: Determine which logs and telemetry are needed to validate or refute the hypothesis.
3. **Execute Queries**: Run detection queries against SIEM and EDR platforms to collect relevant events.
4. **Analyze Results**: Examine query results for anomalies, correlating across multiple data sources.
5. **Validate Findings**: Distinguish true positives from false positives through contextual analysis.
6. **Correlate Activity**: Link findings to broader attack chains and threat actor TTPs.
7. **Document and Report**: Record findings, update detection rules, and recommend response actions.
## Key Concepts
| Concept | Description |
|---------|-------------|
| T1558.003 | Kerberoasting |
| T1558.004 | AS-REP Roasting |
| T1558.001 | Golden Ticket |
## Tools & Systems
| Tool | Purpose |
|------|---------|
| CrowdStrike Falcon | EDR telemetry and threat detection |
| Microsoft Defender for Endpoint | Advanced hunting with KQL |
| Splunk Enterprise | SIEM log analysis with SPL queries |
| Elastic Security | Detection rules and investigation timeline |
| Sysmon | Detailed Windows event monitoring |
| Velociraptor | Endpoint artifact collection and hunting |
| Sigma Rules | Cross-platform detection rule format |
## Common Scenarios
1. **Scenario 1**: Rubeus kerberoast targeting all SPN accounts
2. **Scenario 2**: GetUserSPNs.py from Impacket requesting RC4 tickets
3. **Scenario 3**: Targeted kerberoast against high-privilege service accounts
4. **Scenario 4**: AS-REP roasting accounts without pre-authentication
## Output Format
```
Hunt ID: TH-DETECT-[DATE]-[SEQ]
Technique: T1558.003
Host: [Hostname]
User: [Account context]
Evidence: [Log entries, process trees, network data]
Risk Level: [Critical/High/Medium/Low]
Confidence: [High/Medium/Low]
Recommended Action: [Containment, investigation, monitoring]
```