Analytics Informational

Multiple users authenticated with weak NTLM to a host

Multiple user accounts authenticated to a host via NTLMv1 or LM authentication for the first time in the past 30 days. This may be a result of an NTLM downgrade attack A downgrade attack may force the client to authenticate with a weaker hash/protocol (such as NTLMv1 or even LM) instead of NTLMv2.

Module:
Identity Analytics
Data source:
XDR Agent
ATT&CK tactics: Lateral Movement (TA0008)
ATT&CK techniques: Use Alternate Authentication Material (T1550)
Attacker's goals:

The attacker attempts to gain access to the accounts.

Investigative actions:

Audit all login events with a weaker protocol and review any anomalous usage. Investigate the mentioned host for additional suspicious activity.

Test period:
1 Hour
Deduplication:
1 Day