One File. 33,476 Log Entries. The AltairSupport Stealer Log Had It All.

In August 2025, analysts found a stealer log file uploaded to Telegram by an anonymous user operating under the name AltairSupport. Packaged as a so-called private pack, the file held 33,476 records taken directly from infected user devices. Each entry contained an email address, a plaintext password, and a URL, typically pointing to an API endpoint or web service the compromised user had been accessing. The data was methodically collected by infostealer malware and then bundled up for distribution on Telegram.

Why This Is Dangerous

Plaintext passwords are immediately usable. There is no decryption step, no guessing, no waiting. An attacker who downloads this log can start trying email and password combinations against real accounts within minutes. The API URLs included in each record make it even worse, because attackers can identify which specific services, tools, or backend systems each victim was connected to. That information helps them decide which accounts are most valuable to target, whether that is a cloud management console, a corporate email inbox, or an online banking portal.

What Was Exposed in the PRIVATE PACK AltairSupport Stealer Log

• Email addresses
• Plaintext passwords
• API host URLs and web service endpoints

Why This Matters

Even though 33,476 records is smaller than some breaches, the quality of the data makes it highly dangerous. Plaintext credentials paired with specific service URLs give attackers a precise roadmap. They can run credential stuffing tools that automaticaly test each pair across dozens of popular platforms. Successful matches lead to account takeover, identity theft, and sometimes broader corporate intrusions. For anyone whose work credentials were captured on an infected device, the risk extends far beyond personal accounts.

How Stealer Log Breaches Work

Stealer malware gets onto a device in sneaky ways, usually through a fake software installer, a phishing link, or a compromised browser extension. Once it is running, the malware digs through browser password managers, saved login forms, cookies, and any application that stores credentials locally. Everything it finds gets packed into a structured log file and sent off to an attacker-controlled server. That log then makes its way onto Telegram or dark web forums where others can download and use the data.

Check If You Are Affected

HEROIC's free breach scanner searches more than 400 billion compromised records, including stealer logs like this one shared on Telegram. Enter your email address and find out in seconds whether your credentials were part of this or any other known breach. If you are in the database, you will know exactly what to do next. Start your free scan at HEROIC.com.