The Pentagon has suffered from a cyber attack so alarming that it has taken the unprecedented step of banning the use of external hardware devices, such as flash drives and DVD’s, FOX News has learned.

The attack came in the form of a global virus or worm that is spreading rapidly throughout a number of military networks.

“We have detected a global virus for which there has been alerts, and we have seen some of this on our networks,” a Pentagon official told FOX News. “We are now taking steps to mitigate the virus.”

The official could not reveal the source of the attack because that information remains classified.

News.com.au:

The US military has banned the use of flash drives and DVDs on its computers as it tries to combat a virus spreading rapidly through its networks.

The Pentagon ordered an unprecedented ban on all external hardware but refused to comment on the source of the attack, saying such information was classified.

“We have detected a global virus for which there has been alerts, and we have seen some of this on our networks,” a Pentagon official told Fox News.

“We are now taking steps to mitigate the virus.” ...

An email sent to military personnel identified the problem as being caused by a virus called Agent.btz, Wired.com reports.

The virus is a variation of the “SillyFDC” worm, which has been around since about 2005 and spreads by copying itself to flash drives and then replicates onto any computer that device is plugged into.

Agent.btz originated in China, according to ThreatExpert. Spyware Doctor is reported to be capable of eliminating it.