Which command-line option in Hashcat is used to specify a rules file?

• A. -m
• B. -r
• C. -a
• D. -t

Answer: (B)

In Hashcat, you load a set of transformations to mutate candidate passwords on the fly, which can dramatically expand the effective search space without adding more wordlists. The option to specify a rules file tells Hashcat where to find those transformations so it can apply them to each candidate as it generates guesses during the attack. This makes rule-based cracking powerful, since a single word in your wordlist can produce many mutated variants through the rules you provide.

This option is distinct from others that control different aspects of the run. For example, there are options to select the hash type you're targeting and to choose the overall attack mode, which determine what you’re cracking and how you’re generating candidates. Those controls affect the scope and method of the attack, while the rules file option specifically injects predefined transformations into the guessing process. Use it by supplying the path to your rules file in the command line, typically in a form like -r path/to/rulesfile.rule, alongside your wordlist and hash input.