How Malware Led to 409,332 Stolen Logins in Mix Part4

HEROIC's DarkHive intelligence platform has flagged a large-scale stealer log titled Mix Part4, containing 409,332 compromised records. Originally uploaded to Telegram in January 2023, this mixed credential dump aggregates login data stolen from numerous victims across multiple services, all harvested through infostealer malware campaigns.

Plaintext Passwords: No Barrier to Exploitation

Every credential in this leak is stored as plaintext, meaning passwords appear exactly as victims typed them. There is no encryption, hashing, or any form of protection. With over 409,000 readable passwords in a single file, this dump provides cybercriminals with an enormous volume of ready-to-use login credentials the instant they download it.

What Was Exposed

• Email Addresses — Login identifiers spanning multiple email providers and services
• Plaintext Passwords — Unencrypted, readable passwords for each account
• URLs — The specific websites and applications where these credentials grant access

Why Credential Stuffing Makes This Leak Especially Dangerous

With nearly half a million email-password pairs, this dump is a goldmine for credential stuffing attacks. Automated tools cycle through the stolen pairs against banking sites, corporate VPNs, cloud platforms, and social networks. The sheer volume means even a small percentage of password reuse among victims can yield thousands of additional compromised accounts beyond what was directly stolen.

From Malware Infection to Telegram Distribution

The lifecycle of a stealer log begins with infection. Infostealer malware variants like RedLine, Vidar, and Lumma spread through phishing emails, malicious browser extensions, and fake software installers. Once a device is compromised, the malware silently extracts saved passwords, browser cookies, cryptocurrency wallet data, and form autofill information. These harvested credentials are aggregated into log files, which are then sold on dark web forums or shared freely on Telegram channels — as happened with this Mix Part4 dataset.

Check If Your Credentials Were Exposed

With over 400 billion compromised records in its database, HEROIC's free breach scanner can tell you whether your email address or passwords have appeared in this Mix Part4 dump or any of thousands of other known breaches. Searching now and changing any exposed passwords is the fastest way to shut down unauthorized access to your accounts.