The Mayanmar Corp Mails Leak Means Attackers Could Log Into Your Inbox

In February 2026, HEROIC's threat intelligence analysts identified a combolist uploaded to Telegram by an anonymous user, tracked as "MAYANMAR CORP-OTHERS-PRO MAILS TEST SAMPLE uploaded by a Telegram User." The file contains 1,041 records pairing corporate email addresses with plaintext passwords and the URLs of the login portals those credentials belong to.

Why This Is Dangerous

Labeling a file a "test sample" is a common sales tactic used to prove that a larger batch of corporate credentials actually works before the full set is sold elsewhere. Even at this size, the file gives an attacker 1,041 ready-to-use combinations of corporate email address and plaintext password, complete with the exact login URL, meaning no cracking or guessing is required to break in.

What Was Exposed

• Email addresses (corporate mail accounts)
• Plaintext passwords
• URLs linked to each credential pair

Why This Matters

A compromised corporate inbox is a launchpad, not just a mailbox. Attackers who get into one account can send convincing phishing emails to coworkers and clients, redirect invoices, or use the access to move deeper into a company's other systems. If you or your business is one of the 1,041 accounts in this sample, and that password is reused anywhere else, the exposure extends well beyond email.

How Combolist Leaks Work

A combolist bundles email and password pairs, usually formatted as email:password, often with a URL showing exactly which login page the credential opens. Samples like this one are typically posted on Telegram to advertise a larger corporate credential dataset, letting a buyer verify the logins are valid before purchasing the full list. That makes even a modest sample a signal that a much bigger batch of stolen credentials may already be circulating.

Check If You Are Affected

If your organization uses corporate email, it's worth checking now rather than later. HEROIC's free breach scanner searches more than 400 billion exposed records, including this leak, so you can see if your credentials are part of it and reset them before an attacker does.