The Free ULP166 Dump Contains Exactly 501,964 Email and Password Pairs

HEROIC analysts examined the Free ULP166 archive, a URL-Login-Password list uploaded to Telegram in January 2025, and confirmed it contains exactly 501,964 records. Each entry follows the structured ULP format: a URL identifying the target service, an email address serving as the login identifier, and a plaintext password captured directly from an infected machine. This dataset is not a compilation of old breaches -- it is freshly harvested infostealer output, structured for immediate use in automated credential attacks.

Why the Free ULP166 Format Is Particularly Efficient for Attackers

ULP files are the preferred format for credential stuffing operators precisely because they eliminate all ambiguity. Every record specifies the exact target URL, the login credential, and the password -- no guesswork, no additional processing required. With 501,964 structured entries, an attacker running automated tools can begin testing credentials against live platforms within minutes of downloading this archive. The "Free" designation in the filename indicates this was distributed at no cost through Telegram channels, meaning it has likely been downloaded and used by multiple threat actors since January 2025.

Data Exposed in the Free ULP166 Telegram Credential Dump

• Email Addresses -- login identifiers for 501,964 accounts across multiple platforms and servises
• Plaintext Passwords -- directly harvested from infected machines, requiring no cracking or decryption
• URLs -- map each credential pair to the specific platform it was stolen from, enabling precision targeting

The Full Attack Chain: Credential Stuffing, Account Takeover, Identity Theft, Financial Fraud

The structured ULP format makes Free ULP166 a turnkey tool for credential stuffing campaigns. Automated attack frameworks ingest ULP files and systematically test each URL-email-password combination against live login portals. Successful logins trigger account takeover, giving attackers access to inboxes, financial platforms, and any service linked to the compromised account. Password reuse amplifies the damage: a single stolen credential often works across multiple platforms simultaneously. Identity theft follows as attackers extract personal data from compromised accounts, and financial fraud becomes possible once banking portals or payment services linked to the stolen email are accessed. With over half a million records in this single archive, the scale of potential downstream harm is significant.

What Is a ULP File and How Does Free ULP166 Fit Into the Infostealer Ecosystem?

ULP stands for URL, Login, Password -- a structured data format commonly produced by infostealer malware and credential aggregation tools. Infostealers infect machines through phishing, malicious software, or trojanized applications, then harvest credentials from browser password managers, saved logins, and active sessions. The data is formatted into ULP files because this structure is directly compatable with automated credential stuffing tools. Archives like Free ULP166 are numbered sequentially, suggesting they are part of an ongoing series of credential dumps distributed through dedicated Telegram channels. The "Free" prefix indicates distribution without charge, maximizing the number of threat actors who acquire and deploy the data.

Your Email May Be in the Free ULP166 Archive -- Run a Free Scan at HEROIC

HEROIC's breach scanner searches more than 400 billion compromised records, including ULP archives and infostealer dumps like Free ULP166. If your email address appears in this dataset or any known breach, you'll receive an immediate alert. The structured nature of ULP files means that if your credentials are present, an attacker already knows exactly which platform to target. Run your free scan at heroic.com before someone else acts on that information.