The Napoleon Corp UP 420 Leak Exposed 3,922 U.S. Email Accounts on Telegram

HEROIC analysts confirmed that in October 2025, a Telegram user uploaded another batch in the Napoleon Corp stealer log series, designated UP 420. This release exposed 3,922 records containing email addresses, plaintext passwords, and login URLs harvested from compromised machines in the United States. The UP 420 designation indicates this is one of many sequential uploads from the Napoleon Corp operation, which has been consistently distributing stealer log batches through Telegram channels as part of an ongoing credential harvesting and distribution campaign.

Why This Is Dangerous: U.S. Email and Password Combinations Ready for Immediate Use

The 3,922 records in the Napoleon Corp UP 420 dump represent ready-to-use credential pairs targeting U.S.-based accounts. Each record includes a plaintext password alongside the email address and target URL, giving attackers everything they need to attempt unauthorized logins immediately. U.S.-targeted credential sets are particularly valuable because they unlock access to major American financial institutions, healthcare portals, government services, and large e-commerce platforms. The unencrypted password format means attackers face zero technical barriers before launching account takeover attempts.

Data Exposed in the Napoleon Corp UP 420 Stealer Log

• Email Addresses
• Plaintext Passwords
• URLs (U.S. service endpoints and login pages)

Credential Stuffing, Account Takeover, Identity Theft, and Financial Fraud

Napoleon Corp UP 420 credentials enable a rapid multi-stage attack sequence. Automated stuffing tools test all 3,922 credential pairs against major platforms within hours of the file being distributed. Successful logins give attackers access to email inboxes, where they can intercept verification codes and password reset links for financial accounts. Identity theft follows when personal informaton stored in email or cloud services is harvested. Financial fraud escalates when attackers access banking apps, payment platforms, or stored credit card information. Because many users share passwords across multipel services, a single record can compromise dozens of accounts.

Napoleon Corp UP 420: How a Continuing Stealer Operation Targets the U.S.

Napoleon Corp is a persistent infostealer operation that names its uploads sequentially. The UP 420 designation in this batch means it is one of hundreds of releases from this group. Each upload represents a new batch of credentials collected from recently infected machines and packaged for distribution. U.S.-focused batches like this one are assembled by filtering raw stealer output for accounts associated with American email providers and services. The ongoing nature of this operation means that new batches continue to appear on Telegram regularly, adding fresh credentials to the pool available to attackers at any given time.

Check If Your Credentials Are in the Napoleon Corp UP 420 Dump

HEROIC's free breach scanner searches over 400 billion exposed records, including stealer log batches from Napoleon Corp and similar ongoing operations. Enter your email address to find out immediately if your credentials have been exposed in this or any other known breach. Scan your email free at HEROIC and secure your accounts before attackers use this data against you.