How Malware Led to 357 Stolen Logins in the Hotmail.de Dump

HEROIC analysts uncovered a stealer log file targeting Hotmail.de users that appeared on a Telegram channel on July 12, 2026. The dataset contains 357 records, each one representing a set of credentials stolen directly from an infected device by infostealer malware. The exposed data includes email addresses, plaintext passwords, and the URLs where those credentials were entered.

Hotmail.de is the German-language variant of Microsoft's legacy Hotmail email service, still actively used by millions of people. Because these credentials were captured by malware rather than extracted from a server-side breach, they reflect the actual passwords stored in victims' browsers at the moment of infection — making them exceptionally reliable for attackers.

Why Unencrypted Passwords Are a Direct Threat

The passwords in this stealer log are stored in plaintext with no hashing or encryption. This distinction matters enormously: when passwords are hashed, attackers must invest time and computing power to reverse them. With plaintext credentials, that barrier disappears entirely.

An attacker who downloads this file can immediately begin logging into accounts. There is no technical hurdle, no decryption key required, and no delay between obtaining the data and exploiting it. For the 357 people whose credentials appear in this log, the risk of unauthorized account access is immediate and ongoing.

What Was Exposed in the Hotmail.de Dump

• Email Addresses — Hotmail.de email addresses that function as both Microsoft account identifiers and personal communication channels, potentially granting access to OneDrive, Outlook, and other connected Microsoft services.
• Plaintext Passwords — Unencrypted passwords pulled from browser password stores or intercepted during active login sessions, immediately usable without any decryption.
• URLs — The specific websites and login pages where victims entered their credentials, providing attackers with a roadmap of which accounts to target first.

Why Even 357 Compromised Accounts Create a Ripple Effect

A Hotmail.de account is rarely an isolated asset. Microsoft accounts often serve as the gateway to an entire digital ecosystem — email, cloud storage, calendar, contacts, and linked third-party services. Compromising a single Hotmail.de login can give an attacker access to password reset flows for dozens of other accounts.

The threat multiplies further when victims reuse passwords. Security research indicates that the majority of internet users repeat credentials across services. A stolen Hotmail.de password that also works on a banking portal, e-commerce site, or workplace platform transforms a single breach into a multi-account compromise with financial, personal, and professional consequences.

How Stealer Logs Trace Back to Malware on Your Device

Every record in this dataset began with a moment of infection. Infostealer malware typically arrives through phishing emails with malicious attachments, trojanized software downloads, or drive-by exploits on compromised websites. Once executed, the malware quietly inventories the device — extracting saved passwords, session cookies, autofill data, and sometimes even cryptocurrency wallet files.

The harvested data is packaged into a structured log file and sent to the attacker's server. From there, it enters a distribution pipeline. Many logs end up on Telegram, where channels dedicated to sharing stolen data make them available to a broad audience of threat actors. The Hotmail.de file follows this well-established pathway from device infection to public exposure.

Check If Your Credentials Appear in This Leak

If you use or have ever used a Hotmail.de email address, take a moment to verify whether your credentials were captured. HEROIC maintains a free breach scanner that searches more than 400 billion compromised records, including stealer log data like this Hotmail.de dump.

Run a search with your email address to determine your exposure. If your credentials appear, change your Microsoft account password immediately, review your recent account activity for unauthorized access, enable two-factor authentication, and perform a full malware scan on all devices where you have logged into your email.