LeakBase 4,3Kk ULP: 809,042 Passwords Exposed. Yours Might Be One.

HEROIC analysts identified a credential dump known as LeakBase 4,3Kk ULP by firegoon, posted to a hacking forum on May 6, 2024. The file contained roughly 4.3 million total lines, with 809,042 unique records confirmed, each pairing an email address, plaintext password, and the website URL the credentials were used on.

Why an Email, URL, and Plaintext Password Combo Is So Dangerous

This is what's known as a ULP dump, short for URL, login, and password. Instead of just a list of stolen passwords, each record tells an attacker exactly which website a set of credentials unlocks. That removes the guesswork entirely: an attacker does not need to crack a password hash or figure out where to try it, they simply plug the email and password straight into the listed URL and log in.

What the LeakBase 4,3Kk ULP Dump Contains

• Email addresses
• Plaintext passwords
• Website (homepage) URLs

Why This Matters for the 809,042 Affected Accounts

Because this dump pairs each password with the exact site it belongs to, it is built for immediate account takeover rather than analysis or research. If your email address is among the 809,042 unique records, any account tied to that password, especially one you have reused elsewhere, is at risk right now, not just in theory. Attackers running lists like this test them automatically against banking, email, and social media logins within hours of a dump like this circulating.

How a Stealer Log Becomes a ULP Dump Like This

This data originates from stealer log activity, meaning it was harvested from individual devices infected with information-stealing malware rather than taken from one company's breached database. That malware pulls saved logins directly out of a victim's web browser, capturing the password in plaintext along with the URL it was saved for. Once collected from thousands of infected devices, these logs are compiled, deduplicated down to unique entries like the 809,042 here, and sold or shared on forums as a ready-to-use ULP dump.

Check If Your Credentials Are in This Dump

If you think your device might be infected with malware, or you simply want to know whether your email address shows up in a leak like this one, HEROIC's free breach scanner searches a database of more than 400 billion leaked records. Run a quick scan to get an instant answer and change any password you may have reused before someone else uses it against you.