Joe Kasper, Hegseth's former chief of staff, is the latest Department of Defense official rumored to be leaving.

Defense Secretary Pete Hegseth used the Signal app on a personal computer in his office that was connected to the internet on an unsecured commercial line, what’s known as a “dirty line,” two sources confirmed to ABC News Thursday.

Pete Hegseth was barely able to get confirmed as Donald Trump’s Defense secretary, and following a series of scandals — including the revelation that he shared U.S. war plans in a second Signal group chat last month — it’s entirely possible that he will be the first member of Trump’s Cabinet to either resign or be forced out not even 100 days into Trump’s second term.