t-online.de uploaded by a Telegram User: Plaintext Passwords Stolen

HEROIC discovered a stealer log file uploaded by a Telegram user on July 12, 2026, that targeted t-online.de users. The breach exposed 6,693 records containing email addresses, plaintext passwords, and URLs. This data was shared openly on Telegram, making it freely available to anyone looking to exploit stolen credentials.

Why This Is Dangerous

The exposed passwords are stored in plaintext, meaning they require no cracking or decryption to use. Any attacker who downloads this file can immediately log into accounts using the stolen credentials. Because the data also includes the specific URLs where these credentials were used, attackers have a ready-made roadmap to the exact services and websites tied to each victim.

What Was Exposed

• Email addresses linked to t-online.de accounts
• Passwords in plaintext with no encryption or hashing
• URLs revealing which websites and services were accessed

Why This Matters

When passwords are leaked in plaintext alongside email addresses, attackers can launch credential stuffing attacks across hundreds of websites within minutes. If you reuse passwords, a single breach like this can compromise your banking, social media, shopping, and email accounts. Beyond account takeover, the combination of email addresses and browsing history opens the door to targeted phishing and identity theft.

How Stealer Logs Work

Stealer logs are created by malware known as infostealers that silently infect a device, often through fake downloads, malicious email attachments, or compromised websites. Once installed, the malware captures everything you type, including passwords, and records which websites you visit. It packages this stolen data into log files that are then sold or shared on platforms like Telegram. Victims typically have no idea their device has been compromised until their accounts start showing unauthorized activity.

Check If You Are Affected

HEROIC maintains a database of over 400 billion compromised records collected from breaches, stealer logs, and dark web sources. Use the HEROIC data breach scanner to check if your email address or personal information appears in this breach or any other known exposure. Taking action early can help you secure your accounts before attackers strike.