Twitter CEO Jack Dorsey's account was apparently hacked by a group called the Chuckling Squad.
The hacker posted a series of "offensive messages" from Dorsey's including racial fun and "anti-Semitism".
It took Twitter approximately 15 minutes to delete the "inappropriate tweets" from Dorsey's account, and it's still not clear how the hackers gained access. The group shared also a link to a Discord messaging server, but Discord deleted the server within minutes.
The hacked tweets were apparently sent using an SMS messaging service called Cloudhopper. Twitter acquired Cloudhopper in 2010 but the service is no longer available to the public. However Dorsey apparently used a version of the service earlier this year, though most of his tweets are sent from an iPhone.
Twitter said employees are aware of the hack and investigating the source. At 5:22 p.m ET the company said Dorsey's account had been secured and there was no indications that Twitter's systems had been compromised.