TikTok denied a hacker group’s claim that it was able to obtain the source code and user data from the popular video-sharing platform.

The hacker, who goes by the name AgainstTheWest, says they gained access to the personal information of more than 1 billion TikTok users, including users’ PayPal information.

The rumored breach comes during a period of intense scrutiny on TikTok in matters of cybersecurity. The social media app has been accused of spying on users for its Chinese parent company, ByteDance, Last month, a security researcher discovered code in the app that allows TikTok to track users’ keystrokes, including passwords and credit card numbers.

TikTok has insisted that China does not have access to the data of US users and says it takes steps to ensure privacy. The company recently migrated US user data to servers operated by Oracle.