ATP Online Resources Leak Contains Exactly 10,172 Login Pairs

HEROIC analysts identified a dataset attributed to ATP Online Resources, a US-based career and technical training site (atplearningresources.com), that surfaced on a hacking forum around August 26, 2018. The dataset contains 10,172 records pairing email addresses with MD5 password hashes. The source has not been independently verified, and the data appears to have been packaged into a combolist alongside the raw database export.

Why This Is Dangerous

MD5 is an old and weak hashing algorithm. Modern hardware can crack most MD5 hashes in a matter of seconds using precomputed rainbow tables, which means the passwords behind these 10,172 email addresses are effectively exposed in plain text to anyone who wants them. That turns this leak into a ready-made list of working logins that can be tested against other sites.

What Was Exposed

• Email addresses
• Password hashes (MD5)

Why This Matters

Because MD5 is so easy to crack, this leak behaves less like hashed data and more like a plaintext credential list. If any of the 10,172 people in this dataset reused their ATP Online Resources password on an email account, a bank, or a shopping site, an attacker running a credential stuffing attack could get into those accounts too. A single reused password is often the only thing standing between a minor training-site leak and a much bigger identity theft problem.

How Database and Combolist Leaks Work

This incident is tagged as both a database leak and a combolist. The database leak is the original export, likely pulled through a vulnerability in the site's backend or an exposed admin account. From there, criminals typically reformat the raw export into a combolist, a stripped-down file of just emails and passwords designed to be fed straight into automated login tools that test credentials across hundreds of other websites in bulk.

Check If You Are Affected

If you ever created an account with ATP Online Resources, or reuse passwords across multiple sites, it is worth checking your exposure. HEROIC's free breach scanner checks your email against a database of more than 400 billion leaked records, including this one, so you can find out in seconds and change any reused passwords before someone else gets to them first.