The Xavier_Ulp 400200 Stealer Log Means Someone Could Be Logging Into Your Accounts

In March 2026, HEROIC analysts identified a stealer log file uploaded to a private Telegram channel under the name Xavier_Ulp - 400200 Xavier_Group. The file contained 184,513 records, each with an email address, a plaintext password, and the URL of the account those credentials belong to. HEROIC's dark web monitoring team verified the upload on March 12, 2026, and indexed it into our breach database of over 400 billion compromised records.

The 400200 batch is another release in the ongoing Xavier_Group campaign, which has been uploading credential files to Telegram since at least January 2026. Each batch represents a fresh round of harvested logins from compromised devices.

Why the Xavier_Ulp 400200 Stealer Log Means Someone Could Be Logging Into Your Accounts

Stealer logs are not static archives. Within hours of a file like Xavier_Ulp 400200 being posted to Telegram, it is downloaded by dozens of buyers who immediately begin testing the credentials against live websites. If your email and password appear in this file, there is a realistic chance someone has already tried to log into your accounts.

Because the file includes account URLs alongside email addresses and passwords, attackers don't need to run broad tests. They go straight to the sites already listed in the file. If your banking portal, email account, or workplace login is in there, that is the first place an attacker will try. The process is automated, fast, and requires almost no skill from the person running it.

What the Xavier_Ulp 400200 File Exposed

• Email addresses
• Plaintext passwords (no hashing, no encryption, ready to use)
• Account URLs identifying the specific services targeted

184,513 complete credential records, each stolen directly from a device infected with infostealer malware. The passwords in this file were accurate at the time of theft, meaning they worked when they were taken.

Why Stealer Logs Enable Account Takeover Faster Than Any Other Breach Type

Most data breaches expose hashed passwords, which require significant compute time to crack. Even then, many hashes are never successfully reversed. Stealer logs are fundamentally different because the malware captures passwords before they are ever hashed. The data comes out of the browser's storage in its original, usable form.

This means there is no decryption step between the attacker and your account. They have the same credentials you use to log in every day. Combined with the target URL, credential stuffing tools can attempt logins at a rate of thousands per minute across multiple sites simultaneously.

Victims of stealer log credential stuffing often discover the breach only after seeing unexplaned charges, locked accounts, or suspicious outgoing messages from their email.

How the Xavier_Ulp Infostealer Extracted Passwords From Victims' Devices

The Xavier_Ulp campaign relies on infostealer malware that installs on victim devices through deceptive means: fake software downloads, cracked games or utilities, malicious email attachments, or compromised websites. Once running, the malware scans the device for saved credentials in browsers, password fields, and session data.

Chrome, Firefox, Edge, and other major browsers all store saved passwords in local files that infostealers are specifically designed to extract. The malware reads these files, packages the data into a structured log, and transmits it to the attacker's server. The victim's device continues functioning normally throughout this process, with no visible signs of infection in most cases.

The Xavier_Group operation collects these individual device logs and consolidates them into batch files for distribution on Telegram, producing releases like Xavier_Ulp 400200 on a regular and predictible schedule.

Check If Your Accounts Are Already at Risk From the Xavier_Ulp 400200 Leak

If your email address is in the Xavier_Ulp 400200 file, your credentials may already be in use by attackers. Checking now gives you the best chance to act before any damage is done.

HEROIC's free breach scanner checks your email against more than 400 billion compromised records, including this file and all other known Xavier_Group uploads. Enter your email at HEROIC to see if you are affected. If you get a match, change the affected password immediately, use a unique password for every account, and enable two-factor authentication to add a layer of protection that remains effective even when your password is known.