Ntlmv1-multi is a tool tracked across 1 threat cluster and 1 intelligence report mention on ThreatCluster. First observed January 15, 2026; most recent activity January 15, 2026.
Ntlmv1-multi is a cybersecurity tool/kit tied to Net-NTLMv1 authentication, used to test or crack Net-NTLMv1 credentials via rainbow-table techniques. The recent report on 'Closing the Door on Net-NTLMv1' describes releasing rainbow tables to accelerate protocol deprecation, highlighting the practical risk of Net-NTLMv1 in real networks. This underscores the urgency for organizations to disable Net-NTLMv1 and migrate to NTLMv2 or Kerberos.
Mandiant has released rainbow tables that can crack credentials using the Net-NTLMv1 protocol within 12 hours. This legacy Microsoft authentication protocol has been known to expose users to credential theft for over 20…