A WinRAR password cracker is a type of software tool designed to recover or bypass the password protection on RAR (Roshal Archive) files, which are compressed files created using the WinRAR application. These tools employ various methods to attempt to unlock password-protected RAR files, commonly including:

1. Brute Force Attack: This method tries every possible combination of characters until the correct password is found. The time required for this method increases exponentially with the length and complexity of the password.

2. Dictionary Attack: This method uses a predefined list of potential passwords (dictionary) and tests each one. The effectiveness depends on whether the actual password is present in the dictionary.

3. Mask Attack: If part of the password is known or if it follows a specific pattern (like starting with certain characters), this method narrows down the possibilities and tests only the combinations that fit the known pattern.

4. Rainbow Table Attack: This method uses precomputed tables of hash values for possible passwords. It can quickly match the hash of the password, provided it exists in the table. However, it requires a significant amount of storage space.

It's important to note that using such tools to access files without permission is illegal and unethical. They should only be used in scenarios where you have a legitimate right to access the information, such as recovering a forgotten password for your own files. Always respect privacy and intellectual property laws.