Microsoft 9 Stealer Log Leaks 1,397 Login Credentials Online

In early May 2026, HEROIC analysts identified a stealer log file labeled "Microsoft 9," uploaded to a Telegram channel by an unidentified user. The file exposed 1,397 records pairing email addresses with plaintext passwords and the URLs of the login pages they were captured from, most likely including Microsoft account sign-in pages, gathered from devices infected with information-stealing malware.

Why the Microsoft 9 Stealer Log Is Dangerous

This isn't a breach of Microsoft's own systems, it's a batch of stolen logins harvested by malware from individual users' devices and organized under a label referencing Microsoft-related sign-in pages. Because each stolen password is paired with the exact URL it unlocks, an attacker doesn't need to guess where a credential works. With passwords stored in plaintext, no cracking is required: anyone who obtains this file can begin testing logins immediately.

What Was Exposed in the Microsoft 9 Leak

• 1,397 email addresses used as account logins
• Plaintext passwords tied to each email
• The URLs of the login pages, apparently including Microsoft account portals, that each credential pair accessed

Why This Matters If You Use a Microsoft Account

If any of these 1,397 credential pairs belong to an account you still use, and you've reused that password anywhere else, criminals can use it for credential stuffing attacks against your email, cloud storage, or work accounts. Because Microsoft accounts often connect to email, documents, and single sign-on for other services, a compromised Microsoft login can open the door to a much wider range of personal and financial information than the password alone suggests.

How a Stealer Log Like Microsoft 9 Gets Made

Stealer logs come from information-stealing malware that infects a device, typically through a malicious download, cracked software, or phishing link, and then quietly copies usernames, passwords, and browsing data saved in the browser. The malware bundles everything into a file and sends it back to whoever controls the infection. Logs like this one, labeled by the credential types or sites they contain, are then sold, traded, or uploaded to Telegram channels for anyone to download, which is exactly where HEROIC analysts found this one.

Check If Your Credentials Are in the Microsoft 9 Leak

HEROIC's free breach scanner checks your email address against more than 400 billion leaked records, including stealer logs like this one. If your credentials appear in the Microsoft 9 leak or any other breach, you'll get clear steps to secure your accounts. Run a free scan today to find out where you stand.