The specific file you referenced, appears to be a curated collection of these credentials where duplicate entries have been stripped out to increase its efficiency for automated attacks. Understanding Combo Lists
These files are often sold or leaked on the dark web, Telegram channels, and underground hacking forums. How to Protect Yourself
If you are concerned that your information might be in such a list, security experts from Norton Support and Aura recommend:
Hackers use these files for credential stuffing , a type of attack where they use automated software to test the leaked credentials across various websites (like social media, banking, or retail) to find accounts where users have reused their passwords.