krbrst-attack

name	krbrst-attack
description	Kerberoasting is a post-exploitation technique that targets service accounts in Active Directory by requesting Kerberos TGS (Ticket Granting Service) tickets for accounts with Service Principal Names
domain	cybersecurity
subdomain	red-teaming
tags	["red-team","adversary-simulation","mitre-attack","exploitation","post-exploitation","kerberoasting","active-directory","credential-access"]
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	["ID.RA-01","GV.OV-02","DE.AE-07"]

Performing Kerberoasting Attack

Legal Notice: This skill is for authorized security testing and educational purposes only. Unauthorized use against systems you do not own or have written permission to test is illegal and may violate computer fraud laws.

Overview

Kerberoasting is a post-exploitation technique that targets service accounts in Active Directory by requesting Kerberos TGS (Ticket Granting Service) tickets for accounts with Service Principal Names (SPNs) set. These tickets are encrypted with the service account's NTLM hash, allowing offline brute-force cracking without generating failed login events. It is one of the most common privilege escalation paths in AD environments because any domain user can request TGS tickets.

When to Use

• When conducting security assessments that involve performing kerberoasting attack
• When following incident response procedures for related security events
• When performing scheduled security testing or auditing activities
• When validating security controls through hands-on testing

Prerequisites

• Familiarity with red teaming concepts and tools
• Access to a test or lab environment for safe execution
• Python 3.8+ with required dependencies installed
• Appropriate authorization for any testing activities

MITRE ATT&CK Mapping

• T1558.003 - Steal or Forge Kerberos Tickets: Kerberoasting
• T1087.002 - Account Discovery: Domain Account
• T1069.002 - Permission Groups Discovery: Domain Groups

Workflow

Phase 1: SPN Enumeration

1. Enumerate accounts with SPNs using LDAP queries
2. Filter for user accounts (not computer accounts)
3. Identify accounts with elevated privileges (adminCount=1)
4. Prioritize accounts with weak password policies

Phase 2: TGS Ticket Request

1. Request TGS tickets for identified SPN accounts
2. Extract ticket data in crackable format (hashcat/john compatible)
3. Ensure RC4 encryption is requested when possible (easier to crack)
4. Document all requested tickets

Phase 3: Offline Cracking

1. Use hashcat mode 13100 (Kerberos 5 TGS-REP etype 23) for RC4 tickets
2. Use hashcat mode 19700 (Kerberos 5 TGS-REP etype 17) for AES-128
3. Use hashcat mode 19800 (Kerberos 5 TGS-REP etype 18) for AES-256
4. Apply targeted wordlists and rules based on password policy

Phase 4: Credential Validation