Zero-Day Exploit Enabled Cyber-Attack on U.S. Labor Department

In the latest incident of nation-state cyber-attacks, attackers slipped malware onto the agency's site, apparently aiming to compromise nuclear-energy officials from the Department of Energy.

Hackers compromised the U.S. Department of Labor's Website this week, modifying pages about nuclear-related illnesses with malware that could compromise visitors' computers through a zero-day vulnerability in Internet Explorer 8, according to security experts.

While security firms first released details of the attack on May 1, endpoint protection firm Invincea reported on May 3 that the malware served up by the Department of Labor's pages used an exploit for a previously unknown flaw in Internet Explorer 8.

Victims’ systems which fell prey to the attack would be compromised with a variant of Poison Ivy, which is a malware type popular with Chinese hackers. In addition, the command-and-control traffic matches that seen in cases of espionage attributed to a Chinese attacker known as DeepPanda, according to security-management firm AlienVault.

The attack follows reports of the theft of technology secrets, allegedly by Chinese agents, from Western defense firms. These recent attacks highlight the necessity for the U.S. government to address the issue of nation-state espionage, Anup Ghosh, founder and CEO at Invincea, told eWEEK.

"They are essentially stealing defense technology secrets right from under our noses; it's pretty brazen," he said. "At what point, do we as a nation, as a government, say enough is enough, that the red lines are being crossed here?"

The compromise at the Department of Labor appears to be a version of a tactic known as a watering hole attack, where the attackers compromise a site that they believe will be visited by their intended targets. Unlike more general drive-by download attacks, which attempt to compromise as many PCs as possible, watering hole attacks are a form of targeted operation.

In September, security firm Symantec issued an in-depth report on a series of attacks, known as the Elderwood Project, in which attackers applied a number of zero-day exploits and used watering holes to target certain companies or types of companies. In December, attackers compromised the Council of Foreign Relations' Website and used it to serve up malware using an exploit for a previously unknown flaw in Internet Explorer 6, 7 and 8.

While experts cannot be certain that officials at the U.S. Department of Energy were the targets of the attack, the logic is clear, Ghosh said.

"The pages that were compromised with the malware were specific to this issue of workers and nuclear toxicity," he said. "The DOE—and many its labs—do a lot of nuclear research."

As in many cases of targeted attacks, the malware used by the attackers was not well recognized by antivirus software—only 2 out of 46 products identified the malicious executable, according to the initial post by Invincea. Users who believe they may be at risk from this attack should use a different browser or any of a variety of security virtualization products that isolate browsers from the rest of the system.

"Invincea has been notified that Microsoft is aware of this vulnerability and is currently investigating," the company said in its post.