The T_MOBILE_DME Combolist Sat Hidden 3 Years Before Surfacing

HEROIC analysts identified a combolist file labeled T_MOBILE_DME_43MMCELLS_02 circulating on Telegram, tagged internally with a leak date of August 2023. The file contains 854,685 records pairing email addresses, plaintext passwords, and associated URLs, credentials pulled together from earlier breaches and repackaged into a single list for cybercriminals to use. Why this is dangerous: because the passwords in this file are stored in plaintext, anyone who obtains it can immediately try each email and password pair against other accounts, with no cracking or decryption needed. The URLs included alongside each record often reveal the specific site or service each credential pair unlocks, giving an attacker a direct route into the accounts tied to your email address. What was exposed: email addresses, plaintext passwords, and associated URLs or login links. Why this matters: combolists like this one are commonly used for credential stuffing attacks, where automated tools test stolen email and password pairs against banking sites, email providers, and social media platforms. Because this data has been circulating for years, some of it may already have been tried against other services, and any accounts still using the exposed password remain at risk of account takeover, identity theft, or financial fraud. How combolists work: a combolist is a compiled text file that pairs email addresses or usernames with passwords, gathered from multiple earlier breaches or malware infections and merged into one master list. Criminals build and trade these lists on Telegram channels and dark web forums because it saves them the work of hunting down credentials one breach at a time, and once a combolist is created it can resurface and recirculate for years after the original data was first stolen. Check if you are affected: with over 400 billion records in its database, HEROIC's free breach scanner can tell you in seconds whether your email address appears in this leak or any other breach on record. If it does, HEROIC will show you exactly what data was exposed so you can change passwords and secure your accounts before someone else uses them against you.