Analytics Informational

NTLM Relay

An NTLM NTProofStr was seen from more than one source. This indicates that NTLM authentication data has been relayed.

Module:
Platform Analytics
Data source:
Palo Alto Networks Firewall traffic Logs, XDR Agent
ATT&CK tactics: Credential Access (TA0006) Lateral Movement (TA0008)
ATT&CK techniques: Adversary-in-the-Middle: LLMNR/NBT-NS Poisoning and SMB Relay (T1557.001) Use Alternate Authentication Material: Pass the Hash (T1550.002)
Attacker's goals:

The attacker is attempting a man-in-the-middle NTLM relay attack to intercept authentication attempts and move laterally within an environment.

Investigative actions:

Check that the alerted host is not a NAT or a proxy that duplicates traffic as part of its normal behavior. Check if the protocols used are vulnerable to an NTLM relay attack (e.g. LDAP, SMB). Ensure that SMB signing is enabled in the case of a possible SMB relay attack.

Test period:
10 Minutes
Deduplication:
1 Day