Your Data May Be Exposed: The Bigdatacomboo Leak Hit 65,574 Accounts

HEROIC analysts identified a large combolist labeled "New Valid Bigdatacomboo" that a Telegram user uploaded on June 13, 2025. The file contains 65,574 records, each pairing an email address with a plaintext password and the URL the credentials belong to, and it is being marketed as containing only currently working, "valid" logins. Why this is dangerous: the "valid" label in this file's name signals that whoever compiled it already tested the credentials and confirmed they still work, which makes this list significantly more dangerous than an average combolist scraped from old breaches. Combined with plaintext passwords and ready-to-use URLs, an attacker can begin logging into accounts immediately with a high expected success rate. What was exposed: the dataset includes email addresses, plaintext passwords, and the URLs tied to each account, all marketed as pre-verified and working, giving attackers a high-confidence target list across all 65,574 records. Why this matters: a large, pre-verified combolist like this one is exactly what powers credential stuffing attacks at scale, automated tools testing tens of thousands of confirmed logins against banking sites, email providers, and social media platforms within hours. Because so many people reuse passwords, a single working credential pair can open the door to account takeover, identity theft, and financial fraud far beyond the original account. How this combolist was built: large "valid" combolists are typically produced by running huge batches of stolen credentials, sourced from older breaches, stealer malware, or phishing campaigns, through automated checker tools that test each login and discard anything that no longer works. What remains is a smaller but far more dangerous file of confirmed, currently functioning credentials, which is exactly what makes lists labeled "new" and "valid" more valuable and more actively traded on Telegram. Check if you are affected: because this file is specifically made up of verified working logins, it is especially important to check whether your email address is included. HEROIC's free breach scanner searches more than 400 billion leaked records, giving you an instant answer so you can change any exposed passwords before someone else logs in first.