Mandiant has released a set of rainbow tables that significantly simplify the process of hacking NTLMv1 administrative passwords. This development allows attackers to recover authentication keys in less than 12 hours using consumer-grade hardware, which can cost under $600. Previously, exploiting NTLMv1 required either expensive hardware for brute-force attacks or sending sensitive data to third-party services. By making these tools more accessible, Mandiant has effectively transformed NTLMv1 from a theoretical vulnerability into a practical method for a wider array of threat actors. The vulnerability lies in NTLMv1's use of known plaintext attacks. When an attacker captures a Net-NTLMv1 hash without Extended Session Security (ESS) for the plaintext value "1122334455667788," they can recover the password hash through cryptographic methods. The attack often starts with coercing authentication from high-value targets like domain controllers using tools such as PetitPotam. Once the attackers have the hashes, they preprocess them and utilize Mandiant’s rainbow tables through programs like RainbowCrack to extract the DES keys necessary for further exploits, including DCSync attacks. Mandiant's dataset is available via the Google Cloud Research Dataset portal, with SHA512 checksums for integrity verification. The community has already begun creating optimized versions for both CPU and GPU, further enhancing the toolkit available to attackers. Immediate mitigation strategies for organizations include disabling NTLMv1 entirely and ensuring systems are configured to respond only with NTLMv2. However, local configurations can be altered by attackers with admin access, underscoring the need for ongoing monitoring and detection beyond just policy enforcement.