Coercing Authentication
Last updated
Last updated
The demonstrates performing this attack with CrackMapExec, however, it can also be performed by crafting a custom .LNK file.
1. Enumerate the hosts shares
2. Create a malicious .LNK file calling back to your Responder.py IP
3. After waiting and (hopefully) obtaining several NTLM hashes, cleanup the malicious file
Put an underscore as the first character in the file name (e.g., NAME=_bonus.xlsx and it will put the file at the top of the directory, making it more likely to render and send a hash to the malicious server.
If a machine that we have compromised is configured with we are able to capture any of the TGTs from machines/accounts that have authenticated to it. If we're able to obtain a TGT from a machine account, we can craft service tickets and obtain administrative access to it - this also works for domain controllers.
It should be noted that in order to successfully exploit the printer bug, we must have already obtained a session as or valid domain user credentials.
Enumerate Print Spooler service with ItWasAllADream:
1. We first need to monitor for any new TGTs on the system that has unconstrained delegation configured. Rubeus provides us with the handy functionality to accomplish this:
2. We can then execute SpoolSample.exe on the host to coerce authentication:
3. After running SpoolSample.exe we should then aobserve a TGT on the attacker controlled system.
Alternatively, we can accomplish this same exploitation path remotely using Impacket's ntlmrelayx to relay the credentials:
1. The tester first identifies all of the domain controllers in the domain, this can be done either through DNS or by identifying common ports associated with DC's such as 88/tcp.
2. Modify the configuration of your Responder installation so that the challenge paramter is set to the following value and run Responder in Analyze mode with the --lm flag to attempt to downgrade the authentication:
3. The tester can then attempt to force authentication from the domain controllers to the attacker controlled server using PetitPotam:
4. The output received should look like the following:
While itself has been rendered a little redundant due to tools like Coercer accomplishing the same, yet more. It is still important to discuss as it's still all that's needed to of Active Directory environments. One of the most simple yet effective attack paths with PetitPotam would look like the following:
5. With the NTLMv1 hash now retrieved, the tester can utilize the tool to obtain the appropriate format for cracking:
6. This hash can then be cracked via Hashcat with the instructions displayed on screen or alternatively can be submitted to .
is a Python script which automagically attempt to coerce an arbitrary machine to an attacker controlled device in several ways.
