Anthropic-Cybersecurity-Skills/skills/detecting-kerberoasting-attacks/SKILL.md

name, description, domain, subdomain, tags, version, author, license, d3fend_techniques, nist_csf, mitre_attack

name	description	domain	subdomain	tags	version	author	license	d3fend_techniques	nist_csf	mitre_attack
detecting-kerberoasting-attacks	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.	cybersecurity	threat-hunting	threat-hunting mitre-attack kerberoasting credential-access kerberos t1558 proactive-detection	1.0	mahipal	Apache-2.0	Application Protocol Command Analysis Network Isolation Network Traffic Analysis Client-server Payload Profiling Network Traffic Community Deviation	DE.CM-01 DE.AE-02 DE.AE-07 ID.RA-05	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]