The LeakBase Firegoon Dump Put 2.7 Million Stolen Credentials Online

On December 7, 2024, a threat actor operating under the handle firegoon posted a stealer log titled "23Kk Url:log:pass" to a prominent underground forum. The dump, cataloged as the LeakBase 23Kk ULP, contained approximately 23 million raw lines and surfaced 2,744,797 unique email addresses paired with plaintext passwords and associated homepage URLs. Unlike breaches where hashed passwords must be cracked before they can be used, plaintext credentials are immediately weaponizable, meaning anyone who downloaded this file could attempt logins across hundreds of services within hours of the post going live.

Why This Stealer Log Is Dangerous

Stealer logs are built by infostealer malware running silently on infected endpoints. The malware scrapes saved browser credentials, active session cookies, and autofill data before packaging everything into a structured log file. Because the credentials are copied directly from the browser's credential store, they arrive in the dump already in plaintext -- no cracking required. The LeakBase 23Kk ULP is a textbook example: email, password, and the associated URL are bundled together, giving an attacker everything needed to attempt an instant login on that exact site or to pivot to other services where the same password is reused.

What Was Exposed

• Email Addresses -- 2,744,797 unique addresses, usable as attack targets or for phishing
• Plaintext Passwords -- unencrypted, immediately ready for credential stuffing or direct login attempts
• Homepage URLs -- the specific sites where the credentials were captured, enabling precise account targeting

Why This Matters

When an attacker holds a plaintext email-password-URL triplet, the chain of harm is short:

• Direct account takeover -- the attacker logs straight into the site listed in the URL using the captured credentials
• Credential stuffing at scale -- automated tools test the same email-password pair against banking, email, and social media platforms within minutes
• Identity theft and fraud -- access to email accounts unlocks password resets across every linked service, enabling full account takeover chains
• Targeted phishing -- knowing a victim's email and the sites they use allows attackers to craft highly convincing lure messages

How Stealer Log Breaches Work

Infostealer malware typically arrives via phishing emails, trojanized software downloads, or malicious browser extensions. Once installed, it operates in the background, harvesting credentials from Chrome, Firefox, Edge, and other browsers. The collected data is transmitted to an attacker-controlled server and eventually compiled into a log file. Threat actors then sell, trade, or -- as in this case -- publicly post the logs on underground forums to build reputation or monetize the data. The LeakBase 23Kk ULP represents one such public release, meaning the data was freely available to any forum member who downloaded it.

Check If You Are Affected

HEROIC's breach intelligence database indexes over 400 billion compromised records, including stealer log compilations like the LeakBase 23Kk ULP. If your email address or your organization's domain appears in this dump, you need to know now -- before an attacker uses it.

Search your email address free at heroic.com and see instantly whether your credentials have been exposed. For organizations, HEROIC offers continuous monitoring that alerts your team the moment a new employee credential surfaces in a fresh breach.