Password Reusers Are the Target: ARCEUSULP 155 Exposed 741,107 Records

HEROIC analysts identified a combolist named ARCEUSULP 155 that was uploaded to a Telegram channel on July 28, 2026. The file contained 741,107 records made up of email addresses, plaintext passwords, and the URLs those credentials were used on. Why This Is Dangerous: The real target of a combolist like ARCEUSULP 155 is not any one company or industry, it is anyone who has ever reused a password. Because the credentials are stored in plaintext and organized as ready-to-use pairs, an attacker can load the file straight into automated tools and start testing logins across hundreds of sites without any technical effort. What Was Exposed: - Email addresses - Plaintext passwords - URLs tied to each set of credentials Why This Matters: With 741,107 records in one file, ARCEUSULP 155 gives attackers plenty of raw material for credential stuffing, the practice of testing stolen email and password pairs against banking sites, email providers, and online stores to see which ones still work. If you have ever used the same password on more than one account, a leak of this size puts you squarely in the group of people at risk of account takeover, financial fraud, and identity theft. How a Combolist Like This Works: A combolist like ARCEUSULP 155 is built by combining email and password pairs gathered from earlier breaches, stealer logs, and phishing pages into a single large file. These lists are often organized so that a higher share of the credentials still work, which is what makes them valuable to attackers and part of why files this size circulate on Telegram within hours of being compiled. Check If You Are Affected: HEROIC's free breach scanner checks your email against more than 400 billion leaked records, including large combolists like ARCEUSULP 155, so you can find out in seconds if you are one of the 741,107 people affected. Run a free scan today and change any password you have reused across multiple sites.