Password Cracking

Adversaries may use password cracking to attempt to recover usable credentials, such as plaintext passwords, when credential material such as password hashes are obtained. OS Credential Dumping is used to obtain password hashes, this may only get an adversary so far when Pass the Hash is not an option. Techniques to systematically guess the passwords used to compute hashes are available, or the adversary may use a pre-computed rainbow table to crack hashes. Cracking hashes is usually done on adversary-controlled systems outside of the target network. The resulting plaintext password resulting from a successfully cracked hash may be used to log into systems, resources, and services in which the account has access.

Example:

Password Cracking has been a great method to retrieve passwords offline, a technique used to not lock out accounts and leave logs off multiple attempts in an environment.

Some tools known for this attack are Aircrack-ng, Hashcat, John, Medusa, Ncrack, etc. In this example I will use John The Ripper just for a simple demonstration on how hashes can be cracked.

Simply by grabbing a sample of an NTLM hash file(You do not explicitly need this type but I will use this) and run it against john and a wordlist we can crack the hash and receive a password.