How the CuckooLogsPublic-20251205 Stealer Log Was Created

Security analysts found that in December 2025, a Telegram user uploaded a stealer log file labeled CuckooLogsPublic-20251205 that exposed 14,945 records. The dataset contained email addresses, plaintext passwords, and the URLs associated with each credential pair -- all harvested from infected machines by infostealer malware before being made publicly available on Telegram.

With nearly 15,000 credential pairs in this single file alone, and each record pointing directly to a specific website, attackers have a ready-made list for automated login attempts. There's no decryption needed, no guessing required -- just a script and a list of targets that came pre-labeled by the malware itself.

CuckooLogsPublic-20251205 Breach: The Full Data Inventory

• Email Addresses
• Plaintext Passwords (no hashing, fully readable)
• URLs (the exact target sites tied to each credential)
• API endpoints and host data

Account Takeover Risk From CuckooLogsPublic-20251205

When attackers get a file like this, the first thing they do is run credential stuffing against high-value targets -- email providers, banking portals, and e-commerce platforms. Because the URLs are included in the log, they can filter records by target site and prioritize the most valueable accounts first.

Identity theft is the next stage. With a working email and password, criminals can trigger password reset flows on other accounts, intercept 2FA codes sent via email, and gain access to services that were never in the original log. One compromised credential pair can unlock dozens of accounts if the victim reused passwords.

How Stealer log Data Gets Collected and Sold

Infostealer malware -- tools like Cuckoo, Redline, and Raccoon -- infects computers through trojanized software, phishing links, and drive-by downloads on malicous websites. Once active, the malware harvests browser-stored passwords, cookies, and autofill data, then uploads everything to a remote collection server.

The name CuckooLogs in this file strongly suggests the Cuckoo infostealer family was involved in collecting these records. Operators of such malware routinely package logs by date and release batches publicly to attract attention in underground communities -- the "Public" label in the filename confirms this was intentionally made free to access rather than sold privately.

See If Your Account Appeared in the CuckooLogsPublic-20251205 Leak

HEROIC's free breach search checks your email against more than 400 billion exposed records, including recent stealer log drops like this one from December 2025. If your credentials appeared in this file, you need to change those passwords now before they get used against you. Search your email address today and get a complete picture of where your data has been compromised.