These are compiled from multiple historical data breaches and sold or shared in the criminal underground for brute-force attacks.
If you are concerned your own email is on one of these lists: Download 517K PRIVATE COMBOLIST EMAILPASS zip
A "combolist" is a text file containing massive lists of username/email and password combinations, usually formatted as email:password . These are compiled from multiple historical data breaches
Use reputable services like Have I Been Pwned to see if your data has been compromised in known breaches. Download 517K PRIVATE COMBOLIST EMAILPASS zip
Some of these lists are monitored by security researchers or law enforcement to track individuals attempting to engage in credential stuffing. How to Protect Yourself