The Naz.API dataset is a massive collection of 1 billion credentials compiled using credential stuffing lists and data stolen by information-stealing malware.
Credential stuffing lists are collections of login name and password pairs stolen from previous data breaches that are used to breach accounts on other sites.
Information-stealing malware attempts to steal a wide variety of data from an infected computer, including credentials saved in browsers, VPN clients, and FTP clients. This type of malware also attempts to steal SSH keys, credit cards, cookies, browsing history, and cryptocurrency wallets.
You can find a password checking utility on haveibeenpwned.com (the tool doesn’t send your password to the server, but only the first 5 characters of the hashed password, which is very safe). There are CLI tools on GitHub you can use to bulk test passwords. They also provide a downloadable list of hashes.
Alternatively, check if your password manager has a built-in tool for checking for passwords in known databases.
Alternatively, just start changing passwords, regardless if they’re in the breach or not. Prioritize the ones with financial information, then the ones with personal info, the ones you visit frequently versus some shitty site you visited once that made you make an account back in 2011, etc.
I know that’s a lot of accounts for some people but you don’t have to do them all at once. Go reset a password or two on a site today at lunch. Then do another one tomorrow. And a few the next day.
I actually remember reading about an app or feature on a password manager that would do something like this. Rather than bark at you to reset 100 different accounts at once, it would just give you 1 or 2 random accounts a day to go reset the password on.