From DFSCoercer to DA
Attack Environment Setup
For the attack to be successful, there are (4) requirements:
Any valid domain account credentials
Network connectivity to the target SMB (Server Message Block) Service.
The target host must be running the Print Spooler service
The target host must be allowed to send NTLMv1 responses (cannot be set to enforce NTLMv2 responses)
To determine if NTLM responses can be sent, I will check secpol.msc at Security Settings\Local Policies\Security Options\Network security: LANManager authentication level. Vulnerable settings can be any of the following:
- Send LM& NTLM responses
- Send LM& NTLM – use NTLMv2 session security if negotiated
- SendNTLM responses only.
Step1: set responder challenge
First, ensure that Responder’s challenge is set to 1122334455667788 in Responder.conf:
Step2: Start Responder
--disabled-ess and --lm
This is because the captured hash is NTLMv1 with SSP(Security Support Provider), which changes the server challenge and is not quite ideal for the attack. We can use Responder’s LanMan downgrade flag to get a NTLMv1 hash without SSP.
Step3: Use Coercer to test and execute the attack
Before starting, we can use crackmapexec to test if the spooler service in enabled.
Step4: Machine hash obtained
Now that the DC’s NTLMv1 hash has been captured, it can be cracked back into a plain NTLM hash, compatible with pass-the-hash attacks.This can be done quickly by submitting NTHASH:<response>to crack.sh, which uses rainbow tables, or by manually reconstructing the NTLM hash from its DES elements using hashcat and EvilMog’s ntlmv1-multi tool (my hashcat rig with an NVIDIA 3090 takes around 16 days to brute-force the needed DES hashes).
Step5: Preparing the hash
Step 6: Cracking it or submit it to crack.sh
Cracking it online:
Hashcat:
Use this charset:
2. Create a file with the following content from step5:
3. Execute hashcat
Step7: NTLM hash obtained + secrets dump
After obtaining the cracked NTLM hash, we need to find out the target user. We can dump the domain users with ldapdump or bloodhound before. When a domain admin account is picked up, we just need to execute the following command (DSync attack):
The NTLM account of the domain admin can be obtained.
Step8: Dump AD users
impacket-secretsdump -just-dc-ntlm domain/user@10.0.0.6
Step9: Password cracking
python3 script_passwords.py hashes.txt cracked.txt
The ouput.txt file is generated with all the NTLM hashes, including repetitions.
Finally, the top of passwords can be see:
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