Hackers reportedly attempted a brazen attack on a White House military network in charge of the president’s nuclear football.

US officials familiar with the incident said unidentified hackers launched an attack early last month on the network used by the White House Military Office (WHMO), an military office in charge of sensitive communications, including systems to send and authenticate nuclear strike commands. The office is also responsible for arranging presidential communications and travel. However it seems only less significant systems were targeted by an assault that was, in any case, ultimately unsuccessful.

An unnamed Obama national security official said: "This was a spear phishing attack against an unclassified network."

"In this instance the attack was identified, the system was isolated, and there is no indication whatsoever that any exfiltration of data took place," the official said, the Washington Free Beacon (a Conservative blog that broke the story) reports.

Follow-up reports suggest that a dodgy email with a malicious attachment made it past perimeter defences and onto someone's desktop, where it might have been opened, and a machine infected. But this machine was quickly identified and isolated before any damage was done.

Rob Rachwald, director of security strategy at Imperva, said the attempted attack should nonetheless act as a wake up call.

"Yet again traditional security software has failed to keep the bad guys out. Enterprise needed to assume that they have been compromised which means we need to detect abnormal access to data and Intellectual Property. This is yet another example of why we need to rethink the current security model and implement a new one that puts cameras on sensitive information."

The attack was launched from Chinese networks, which by itself doesn't mean much. However some officials seem to reckon the Chinese military cyber warfare specialists, working as part of a unit called the 4th Department of General Staff of the People’s Liberation Army, or 4PLA, are the most likely suspects behind the attack. ®