The United States' Department of Labor's Website has been breached and is serving up malware in drive-by-download attacks, security researchers warned.
When a visitor lands on the impacted area of the Labor Department's Website, an infected script collects information about the computer and downloads a customized payload, Jamie Blasco, director of AlienVault labs, wrote in a blog post Wednesday. It appears the infection began sometime late April 30 but has been removed by mid-Wednesday.
"The site has since been fixed and law enforcement is investigating," Anup Ghosh, CEO of Invincea, wrote in a blog post Wednesday.
The malware targeted a user-after-free vulnerability in Microsoft Internet Explorer version 6 through 8 (CVE-2012-4792) which Microsoft had patched earlier this year. The vulnerability had originally been reported in December as part of a series of high-profile zero-day attacks.
This appears to be another watering hole attack, with attackers infecting specific targets by compromising Websites they may visit. "The vast majority of web-based drive by exploits are occurring from legitimate websites that are compromised with the specific intention to exploit the website visitors," Ghosh said.
If the malware successfully exploited the IE flaw, it downloaded a "variant of Poison Ivy remote access Trojan" that has been modified to evade detection. According to VirusTotal, the malware is currently being flagged by only 13 out of 46 antivirus scanners.
The PHP script, found on the Site Exposure Matrices microsite, collected information such as which version of the Adobe Flash plugin, the names and version of PDF plugins, and the version of Microsoft Office, were installed on the victim's computer, according to AlienVault. The script also checked if the visitor had antivirus programs from popular vendors such as McAfee and AVG installed, and attempts disable the free antivirus scanner from BitDefender.
The protocol matches a backdoor used by a known Chinese hacker called DeepPanda, Blasco said, who also noted the similarities in this attack and the ones earlier this year against a Thailand-based non-governmental organization.