The BlackCat (ALPHV) ransomware gang has taken responsibility for a breach at social media giant Reddit earlier this year and is threatening to leak 80GB of data stolen from the company if a $4.5 million ransom demand is not paid.

The group is also demanding that Reddit roll back its controversial decision to charge for access to its API. The Reddit APIs offer access to its data for third-party apps to build user utilities, research, and games. Effective July 1, the updated rules would require third-party apps to pay approximately $1 per user per month for API access.

This decision sparked a massive protest, with nearly 8,000 communities on the platform going dark at one time.

A Reddit spokesperson declined to comment on the matter but confirmed that BlackCat’s claim is related to a security breach in February 2023.

In a February blog post Reddit revealed it was the victim of a phishing campaign where attackers stole data from its internal systems after obtaining an employee’s credentials. The stolen information is said to have included “limited Reddit code, limited contact information for a small number of company contacts and employees (current and former), as well as limited advertiser information (no high-risk data was accessed such as credit card details, company financial information, account passwords, campaign strategy or performance).”

The BlackCat gang says it made two attempts to contact the company - in April and June - but “there was no attempt to find out what we took.”