Disk-Wiping 'Shamoon' Malware Resurfaces With File-Erasing Malware in Tow

Organizations in the United Arab Emirates and Saudi Arabia are once again being targeted in a new wave of attacks involving Shamoon, a malware strain that was used to destroy more than 30,000 PCs at oil giant Saudi Aramco in 2012.

The latest attacks come after a two-year lull and are doubly destructive since they include a new component, Filerase, for erasing files on an infected system before Shamoon wipes the master boot record clean, Symantec states in a report. The addition of Filerase makes it almost impossible for victims to recover data from impacted systems, the security vendor notes.

Based on a breach disclosure from Italian oil services firm Saipam, the new Shamoon attacks appear to have begun Dec. 10. Saipam, a leading provider of drilling services, described the attack as impacting up to 100 PCs and between 300 and 400 servers located in the Middle East, India, Scotland, and Italy.

"The attack led to the cancellation of data and infrastructures, typical effects of malware," according to Saipem. "The restoration activities, in a gradual and controlled manner, are under way through the back-up infrastructures and, when completed, will re-establish the full operation of the impacted sites." Reuters quoted a Saipem executive as saying the attacks had originated in the south Indian city of Chennai, though Symantec itself says it has no evidence to corroborate.

However, according to Symantec, its researchers have found evidence of attacks against at least two other organizations in the oil and gas industry in the Middle East during the same time.

Eric Chien, senior researcher at Symantec, says the company is still early in the investigation process and has so far been unable to determine whether the same group that was behind the original Shamoon attacks is behind the latest ones as well.

One of the companies impacted in the latest attacks was also recently attacked by Elfin/APT 33, an Iranian threat group that has been targeting aerospace and energy-sector targets. The proximity of the two attacks makes it possible the two campaigns are linked, Chien says.

The Hunt for Motives
At this time it's unclear why the companies were targeted and how the attackers are distributing Shamoon and the new Fireraser component. Chien describes Filerase as deleting files in [ROOT_DRIVE]\Users and on other drives that are less than 100 MB in size.

Once Filerase infects one system, it spreads across the victim network using a list of targeted systems and another tool called Spreader.exe. The list, in the form of a text file, is specific to each victim and suggests that the attackers likely gathered the information from previous reconnaissance activity on the network, Symantec said. Once Filerase has been successfully copied on all computers in the attacker's list, the Spreader component simultaneously triggers it on the systems.

Symantec says it is possible that Shamoon itself was spread via the same mechanism on the impacted networks. "In at least one instance, Shamoon was executed using PsExec, indicating that the attackers had access to credentials for the network," the company says in its report.

Baan Alsinawi, president and founder of risk management firm TalaTek, says that based on publicly available information about the attack on Saipem, there's a good possibility the attackers had physical access to the Italian company's systems. "The lack of a network component and a command-and-control center, as described, suggested the attacker had installed the malware manually and set a time for it to propagate" she says.

So while it is bad the attackers were able to inflict damage, if they first needed physical access, their ability to impact other companies is going to be somewhat limited, Alsinawi says. Gaining physical access, and likely needing escalated privileges, is a higher bar to achieve in these types of attacks, she says.

This is not the first time Shamoon has resurfaced after disappearing. "We've now seen the malware taken out of retirement every few years," Chien says. After first emerging in 2012 and being used a series of very disruptive attacks against Saudi Aramco and other Saudi energy companies, the malware went dormant before making a comeback in late 2016, he notes.

"With the introduction of this most recent iteration, organizations need to remain vigilant and ensure that all data is properly backed up and a robust security strategy is in place," Chien says.

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