tech
January 19, 2026
Mandiant releases rainbow table that cracks weak admin password in 12 hours
Windows laggards still using the vulnerable hashing function: Your days are numbered.
TL;DR
- Mandiant released an NTLMv1 rainbow table database to expose the weakness of the deprecated hashing algorithm.
- This database allows passwords protected by NTLMv1 to be cracked in under 12 hours using consumer hardware.
- NTLMv1's limited keyspace makes its rainbow tables easier to construct.
- Despite known vulnerabilities since the 1990s, NTLMv1 is still used in sensitive networks due to legacy apps and critical system constraints.
- Mandiant hopes this release will help security professionals convince organizations to migrate to more secure hashing algorithms.
- Microsoft introduced the more secure NTLMv2 in 1998.
- Mandiant advises organizations to immediately disable the use of Net-NTLMv1.