A "combo list," short for combination list, refers to a compilation of usernames or email addresses combined with their corresponding passwords, often used by individuals with malicious intent for unauthorized access to various online accounts. Combo lists are typically created by hackers who have collected login information from data breaches or other sources.
The purpose of a combo list is to automate the process of attempting to breach multiple accounts by trying different combinations of usernames or emails and passwords until a successful match is found. Cybercriminals may use these lists to perform attacks such as "credential stuffing," where they use automated tools to input the credentials from the combo list into various websites or services in an attempt to gain unauthorized access to user accounts.
It's important to note that the use of combo lists for illegal activities is a violation of privacy and often illegal. To protect yourself from such attacks, it's recommended to use strong and unique passwords for each online account, enable two-factor authentication whenever possible, and regularly monitor your accounts for any unauthorized activities.