Inside Hotmail Combo Stealer Logs: 2,166 Passwords Harvested

In October 2024, HEROIC's threat intelligence team identified a stealer log file titled "Hotmail Combo" shared publicly on Telegram. The file contains 2,166 credential records targeting Hotmail users, with all passwords stored in plaintext and accompanied by the exact URLs where they were captured by malware.

Plaintext Storage Eliminates All Password Protection

The 2,166 passwords in this dump are stored in their original plaintext form—exactly as the victims typed them. No hashing algorithm was applied, no salt was added, no encryption protects them. This is characteristic of stealer log data, where malware captures credentials directly from the browser's password store before any server-side security measures can be applied. Each password is exploitable on sight.

What Was Exposed

• Email Addresses — Hotmail account logins that serve as primary identifiers
• Plaintext Passwords — credentials captured pre-transmission by browser-based malware
• URLs — endpoint addresses revealing which login pages the malware was monitoring

How Credential Stuffing Exploits Hotmail Leaks

Hotmail credentials are prized by attackers because Microsoft accounts often serve as recovery emails for other services. With 2,166 email-password combinations, automated credential stuffing tools can test each pair against Microsoft 365, OneDrive, Xbox, LinkedIn, and countless third-party services within minutes. Even one successful match can provide a foothold into a victim's broader digital ecosystem, especially when the same password unlocks multiple platforms.

Technical Anatomy of a Stealer Log Collection

Stealer logs like Hotmail Combo are produced by infostealer trojans such as RedLine, Raccoon, or Vidar. These programs hook into browser processes to intercept saved credentials, cookies, and autofill data. The captured information is structured into standardized log formats—typically organized by URL, username, and password—then uploaded to command-and-control infrastructure. From there, operators curate the data into themed combo lists (in this case, Hotmail-specific) and distribute them through Telegram channels, often for free to build reputation in underground communities.

Check If Your Credentials Were Exposed

Hotmail users should not assume their accounts are safe simply because this dump is relatively small. Use HEROIC's breach scanner to search your email against more than 400 billion compromised records aggregated from thousands of breaches and stealer log collections. A quick search will reveal if your credentials appear in the Hotmail Combo dump or any other known leak, allowing you to rotate passwords and strengthen your defenses immediately.