The account, @BurgerKing, has its profile picture and name changed to McDonald's just after noon Monday and tweets mentioned hacker groups Anonymous and LulzSec, CBS News reported Tuesday.
The posts used the hashtag #OpMadCow, the apparent title given to the hacking operation.
The account was briefly suspended Monday evening and returned with the Burger King logo restored. The tweets from during the hacking were deleted.
"Interesting day here at Burger King, but we're back! Welcome to our new followers. Hope you all stick around!" the company tweeted.
The company did not say if a suspect has been identified in the hacking.