The Homeland Security Department is asking that operators of key U.S. networks follow specific precautions to stave off a virus that last summer erased computers at Middle Eastern oil companies.
A new bulletin for energy producers and other critical infrastructure businesses provides 31 "tactical" and "strategic” repellants for Shamoon, malicious software that wipes out data on infected machines.
In October 2012, then Defense Secretary Leon Panetta called the Shamoon virus “probably the most destructive attack that the private sector has seen to date.”
Much of the new guidance might read like security hygiene 101 to information technology managers, but the pointers reflect insight into how the malicious software targets victims.
For example, DHS officials say that restricting social media at offices in critical sectors could reduce the risk of infection.
“Limit the use of social networking services at work, such as personal email, instant messaging, Facebook, Twitter,” states the federal alert, distributed by a DHS branch that responds to "industrial control system" intrusions.
An earlier DHS bulletin, issued after researchers revealed the malware’s existence in August, reported no evidence that Shamoon "specifically targets industrial control systems' components or U.S. government agencies," but cautioned that it "spreads via network shares to infect additional machines on the network."
The advisory indicates that the bug is keen on traversing systems via administrative accounts and data accessories, such as flash drives. “Prevent or limit the use of all removable media devices on systems to limit the spread or introduction of malicious software and possible exfiltration data,” Homeland Security officials instructed. They also recommended that firms “disable Web and email capabilities on administrative accounts” because the “compromise of admin accounts is one vector that allows malicious activity to become truly persistent in a network environment.”
Unlike the Stuxnet virus that commandeered Iran’s nuclear centrifuges in late 2009, Shamoon does not obliterate industrial operations, but rather erases data.