The Obamacare website was down for six hours the morning of the deadline to register.

The Affordable Care Act's website didn't have enough problems? Someone broke into last month and uploaded malicious software, the Department of Health and Human Services said Thursday. It's not yet known what the malware may have affected, if anything.

"Our review indicates that the server did not contain consumer personal information; data was not transmitted outside the agency, and the website was not specifically targeted. We have taken measures to further strengthen security," the statement said.

According to the statement, the Department of Homeland Security and the FBI investigated the server. Congressional staff were briefed about the attack Aug. 25.

The website failed to operate properly when it launched in late 2013, but most of the tech problems appeared to have been resolved. The attack comes as the federal government and insurance companies get ready for open enrollment, which begins Nov. 15.