Pass the Ticket (PTT) Attack Methodology

Overview

Pass the Ticket (PTT) is an attack technique where you steal a user's authentication ticket instead of their password or hash. The stolen ticket is then used to impersonate the user and gain unauthorized access to resources within a network.

Why use PTT?

• No password or hash required
• Works even with strong password policies
• Bypasses password-based authentication entirely
• Effective against Kerberos-based authentication

Prerequisites

Before executing PTT, you need to obtain a valid Kerberos ticket. See:

• Harvesting tickets from Windows
• Harvesting tickets from Linux

Ticket Format Conversion

Tickets exist in different formats depending on the platform. You'll often need to convert between them.

Linux to Windows (ccache → kirbi)

Use the ticket_converter tool:

python ticket_converter.py input.ccache output.kirbi

This converts Linux ccache format to Windows kirbi format.

Windows to Linux (kirbi → ccache)

python ticket_converter.py input.kirbi output.ccache

On Windows

Use Kekeo for ticket manipulation and conversion.

Executing PTT Attacks

On Linux

1. Export the ticket path

   export KRB5CCNAME=/path/to/your/ticket.krb5cc
   

2. Execute with Impacket

   python psexec.py DOMAIN/username@TARGET_HOST -k -no-pass
   

   • -k

     : Use Kerberos authentication

   • -no-pass

     : No password required (using ticket)

On Windows

1. Load the ticket into memory

   Using Mimikatz:

   mimikatz.exe "kerberos::ptt [ticket.kirbi]"
   

   Using Rubeus:

   .\Rubeus.exe ptt /ticket:[ticket.kirbi]
   

2. Verify the ticket is loaded

   klist
   

   This shows all tickets currently in the cache.

3. Execute commands on target

   .\PsExec.exe -accepteula \\TARGET_HOST cmd
   

Common Scenarios

Scenario 1: You have a TGT (Ticket Granting Ticket)

If you have a TGT for a user, you can:

• Access any resource the user can access
• Request service tickets (TGS) for specific services
• Move laterally across the domain

Scenario 2: You have a TGS (Service Ticket)

If you have a TGS for a specific service:

• You can only access that specific service
• Useful for targeted attacks (e.g., SQL Server, CIFS)

Scenario 3: Cross-platform attacks

If you're attacking from Linux but the target is Windows (or vice versa):

1. Convert the ticket to the appropriate format
2. Load it on your attack platform
3. Execute the attack

Tools Reference

Tool	Platform	Purpose
ticket_converter	Cross-platform	Convert between ccache and kirbi formats
Kekeo	Windows	Ticket manipulation and conversion
Mimikatz	Windows	Load tickets, PTT attacks
Rubeus	Windows	Modern alternative to Mimikatz for Kerberos
Impacket (psexec.py)	Linux	Execute commands using Kerberos tickets
klist	Windows	View cached tickets

Important Notes

• Tickets expire: Kerberos tickets have limited lifetimes. Use them quickly.
• Ticket integrity: Ensure tickets aren't corrupted during transfer/conversion.
• Detection: PTT attacks can be detected. Clear logs and use carefully.
• Privilege escalation: A TGT for a high-privilege user (e.g., Domain Admin) gives you that user's full access.

References

• How to Attack Kerberos - Tarlogic
• Mimikatz Documentation
• Rubeus - PowerSploit
• Impacket - Psexec