To block the attackers, government officials were forced to shut down some of its services, said CNN Money.

This explains why satellite data was mysteriously cut off in October, as well as why the National Ice Center website and others were down for more than a week. During that time, federal officials merely stated a need for "unscheduled maintenance."

Still, NOAA spokesman Scott Smullen insisted that the aftermath of the attack "did not prevent us from delivering forecasts to the public."

Little more is publicly known about the attack, which was first revealed by The Washington Post. It's unclear what damage, if any, was caused by the hack.

But hackers managed to penetrate what's considered one of the most vital aspects of the U.S. government. The nation's military, businesses and local governments all rely on nonstop reports from the U.S. weather service.

The impact of the hack was real, said CNN Money: Scientists at Atmospheric and Environmental Research in Lexington, Massachusetts were unable to send a preliminary report about weather patterns to traders and investors earlier this year.