When a penetration tester obtains a list of password digests using Responder, the next logical step is to attempt to crack these password hashes to retrieve the plaintext passwords. Hashcat is one of the most widely used tools for this purpose. It is a high-performance password recovery tool that supports a wide range of hashing algorithms and can utilize the power of GPU acceleration to significantly speed up the cracking process. Hashcat is preferred over tools like Hydra, CeWL, and Medusa in this context because it is specifically designed for cracking password hashes rather than brute-forcing login credentials (Hydra, Medusa) or generating custom wordlists (CeWL). Reference: Hashcat official website: Hashcat Usage examples in various penetration testing reports, including those involving password cracking and hash manipulation.