File hosting service Dropbox on Tuesday disclosed that it was the victim of a phishing campaign that allowed unidentified threat actors to gain unauthorized access to 130 of its source code repositories on GitHub.

“These repositories included our own copies of third-party libraries slightly modified for use by Dropbox, internal prototypes, and some tools and configuration files used by the security team,” the company revealed in an advisory.

The breach resulted in the access of some API keys used by Dropbox developers as well as “a few thousand names and email addresses belonging to Dropbox employees, current and past customers, sales leads, and vendors.”

The disclosure comes more than a month after both GitHub and CircleCI warned of phishing attacks designed to steal GitHub credentials through fake notifications purporting to be from the CI/CD platform.

The San Francisco-based firm noted that “Multiple Dropboxers received phishing emails impersonating CircleCI” in early October, some of which slipped through its automated spam filters to land in employees’ email inboxes.

“These legitimate-looking emails directed employees to visit a fake CircleCI login page, enter their GitHub username and password, and then use their hardware authentication key to pass a One Time Password to the malicious site,” Dropbox explained.