ARCEUSULP 4 Leak: 1,634,653 Accounts Ready to Steal

In June 2026, HEROIC identified one of the largest individual stealer log files observed this year: ARCEUSULP 4 2619074, distributed on Telegram. The dump contains 1,634,653 records, each one a complete credential set—email address, plaintext password, and URL. At this scale, the file represents a critical threat to individuals and organizations worldwide, with over 1.6 million accounts exposed and ready for exploitation.

1.6 Million Passwords, All in Plaintext

None of the 1,634,653 passwords in this file are protected by hashing or encryption. Every single one appears as the original text the user entered. This means that anyone who downloads ARCEUSULP 4 has instant access to over 1.6 million working login credentials—no password-cracking tools required, no computational investment needed. The scale of immediately exploitable data is extraordinary.

What Was Exposed

• Email Addresses — over 1.6 million account identifiers spanning global services
• Plaintext Passwords — fully readable credentials for immediate unauthorized access
• URLs — the specific login pages and services where each credential was captured

The Devastating Reach of Mass Credential Stuffing

A dump of 1,634,653 credentials is a weapon of mass compromise. Automated credential stuffing operations will process this entire dataset against every major platform—banking, email, cloud services, corporate portals, and social media—within hours. With typical password reuse rates estimated between 50 and 65 percent, hundreds of thousands of additional accounts beyond this dump are at risk of falling to attackers who never needed to hack them directly.

The Infostealer Malware Network Behind ARCEUSULP 4

Producing a dataset of this magnitude requires an extensive network of infostealer malware infections. Thousands of devices were compromised by trojans that harvested credentials from browsers, email clients, FTP applications, and credential stores. Each infected machine contributed its stolen logins to the growing collection, which was ultimately compiled into the ARCEUSULP 4 file and distributed on Telegram—making the combined output of a large-scale malware operation freely available to any threat actor.

Check If Your Credentials Were Exposed

With over 1.6 million records, the probability of your credentials being included is significant. HEROIC's breach scanner indexes more than 400 billion compromised records. Search your email address or domain immediately to check whether your information was part of the ARCEUSULP 4 dump or any other known breach. Change compromised passwords without delay and enforce multi-factor authentication on every account you value.