These files are rarely the result of a single hack. Instead, they are usually compiled through:
: Collecting credentials from unsuspecting users via fake login pages or info-stealing software. Risks and Ethical Implications 104K VALID COMBO.txt
If you are concerned your information might be in a list like this, you should: These files are rarely the result of a single hack
: In the context of "leaked" data, this usually claims that these credentials have been tested (or "checked") against specific services and confirmed to work at the time of the list's creation. How These Lists Are Created How These Lists Are Created : Possessing or
: Possessing or using stolen credentials to access accounts without permission is illegal under acts like the Computer Fraud and Abuse Act (CFAA) in the US and similar laws globally.
: Many files distributed under these names on forums or "dump" sites are laced with malware . The file itself might be a "decoy" designed to infect the person downloading it.