The Hotmail New Part 55 Leak Means Someone Could Be Reading Your Inbox

In February 2023, HEROIC analysts came across a combolist titled Hotmail New Part 55 being distributed on Telegram. The file contained 696,950 records, each pairing an email address with a plaintext password and the URL the credentials belong to. Why the Hotmail New Part 55 leak is dangerous: with nearly 700,000 credential pairs targeting Hotmail and Outlook-style accounts, this file gives attackers a huge pool of working email logins to try. Email accounts are often the key to everything else, password resets, two-factor codes, and personal messages all flow through them, so gaining access to one can unlock a person's entire online life. What was exposed in Hotmail New Part 55: email addresses, plaintext passwords, and URLs tied to each login. What this means if your email is in this leak: someone could be logging into your inbox right now without you knowing. Because email accounts are used to reset passwords for banking, shopping, and social media, an attacker who gets into your Hotmail or Outlook account can pivot from there into nearly every other account you own, enabling account takeover, identity theft, and financial fraud along the way. How a combolist this large gets built: files labeled Part 55 suggest this is one installment in a long-running series, likely compiled over time from multiple smaller breaches and phishing campaigns targeting Hotmail and Outlook users specifically, then split into numbered batches for easier distribution and resale. Check if you are affected: if you use a Hotmail or Outlook address, check it now against HEROIC's free breach scanner, which searches more than 400 billion leaked records to tell you instantly if your credentials have been exposed.