Newsweek's official Twitter page was hacked on Tuesday. CyberCaliphate, a hacker group that claims affiliation with ISIS, was apparently responsible for the attack.
The group hijacked the page's main images and posted a series of tweets, purportedly containing leaked military information. Certain tweets also threatened first lady Michelle Obama and her family. The FBI is investigating the matter, according to the White House.
The tweets were removed about 20 minutes after being posted, when Twitter's support team regained control of the account at the publication's request, according to Newsweek.
The group, whose origins remain unclear, was previously linked to attacks on other media companies' Twitter feeds, as well as at least one U.S. military Twitter account.
Newsweek confirmed the attack and said it had regained control of the account.
"We apologize to our readers for anything offensive that might have been sent from our account during that period, and are working to strengthen our newsroom security measures going forward," the company told CNBC in a statement.
The magazine also disclosed that the website of its sister publication, the International Business Times, was apparently hacked by the group on Tuesday.