Researchers from threat protection firm Bromium were alerted last week by a customer to an attack originating from the website of a high-profile technology startup in the oil and gas sector.
According to Bromium, the attackers planted malicious code on a United States-based company’s website in an effort to infect the computers of its visitors, an attack known as a watering hole attack.
According to experts, it’s possible that the targeted company, which has not been named, attracted the attention of the attackers since it had announced a considerable funding grant just days before the attack.
“It’s likely that the attackers were expecting more traffic to the website and hoped to increase their chances of a successful infection,” Bromium’s Vadim Kotov explained in a blog post.
Rahul Kashyap, chief security architect and head of research at Bromium, told SecurityWeek that the attackers might have hoped that the computers of other companies in the oil and natural gas sector would become infected as a result of the watering hole attack.
The malicious script placed on the compromised website leveraged a low-severity Internet Explorer vulnerability to check for the presence of security solutions from Trend Micro and Kaspersky Lab. The vulnerability in question, CVE-2013-7331, is an information disclosure vulnerability that allows resources loaded into memory to be queried. It can be exploited to detect the anti-malware applications that are in use on a targeted system.
The issue was addressed by Microsoft with this month’s security updates, but threat actors have been exploiting it in the wild since at least February when FireEye researchers documented an attack against American military personnel. At the time, the exploit was used to detect the presence of Microsoft’s Enhanced Mitigation Experience Toolkit (EMET).
At the time of the attack analyzed by Bromium, the vulnerability was not patched, and researchers believe the attackers might have tested for the presence of Kaspersky and Trend Micro solutions because they detect the malware being served.
Visitors of the oil and gas company’s website were redirected to a drive-by download page hosting the Sweet Orange exploit kit, which attempts to exploit Java, Flash and Internet Explorer vulnerabilities in an effort to push malware.
The dropped Trojan has a Windows folder icon, most likely to avoid raising any suspicion. The threat is designed to check the infected system for the presence of virtual machines, sandboxes and other applications that might be used by security researchers, such as Wireshark and Process Monitor.
The final payload used in this campaign is a Trojan that downloads other pieces of malware from the command and control server to the infected machine.
“The authors of this attack paid a lot of attention to stealthiness, starting from [a] cookie-based redirect and driver fingerprinting to monitoring tools detection. This might narrow down the target audience of the attackers but improve the success rate. Which makes perfect sense – there are plenty of vulnerable machines out there – why bother infecting protected ones?” Kotov said.
The investigation into this operation is still ongoing so Bromium could not provide too much information on the attackers. However, Kashyap says the command and control server used in the attack is located in Luxembourg.