Cit0Day.in

Cit0Day.in operated as a cybercrime service that aggregated hacked databases and sold access to them for a fee. Its primary customers were malicious actors seeking large collections of compromised credentials for further attacks. The service collected data from both obscure and prominent historical breaches, compiling them into a searchable index. By providing paid access to this repository, it facilitated the reuse of stolen information across numerous online platforms. The scale of its holdings was explicitly noted as 23,618 databases containing billions of user records, including emails, usernames, addresses and cleartext passwords. This volume positioned it as one of the larger known repositories of breached data at the time of its operation.

Following its shutdown, Cit0Day.in experienced a massive leak of its entire collection on 14 September 2020, releasing the 23,618 databases that comprised billions of user records. The leaked data was distributed across hacking forums, private channels, file‑sharing platforms and messaging applications. Although a fabricated seizure notice initially prompted speculation about law‑enforcement involvement, the leak proceeded regardless of that rumor. The broad availability of the information allowed threat actors to launch credential stuffing, password spraying and spam campaigns on a large scale. Because the records contained cleartext passwords, the leak increased the likelihood that credentials reused on other services would be compromised. The episode demonstrated how a centralized repository of breached data, once uncontrolled, can amplify risks across numerous online accounts.