Flame authors order infected computers to remove all traces of the malware
Flame self-desctruct module overwrites file data to prevent forensic analysis
IDG News Service - The creators of the Flame cyber-espionage threat ordered infected computers still under their control to download and execute a component designed to remove all traces of the malware and prevent forensic analysis, security researchers from Symantec said on Wednesday.
Flame has a built-in feature called SUICIDE that can be used to uninstall the malware from infected computers. However, late last week, Flame's creators decided to distribute a different self-removal module to infected computers that connected to servers still under their control, Symantec's security response team said in a blog post.
The module is called browse32.ocx and its most recent version was created on May 9, 2012. "It is unknown why the malware authors decided not to use the SUICIDE functionality, and instead make Flamer perform explicit actions based on a new module," the Symantec researchers said.
However, even though it is similar in functionality to the SUICIDE feature -- both being able to delete a large number of files associated with the malware -- the new module goes a step further.
"It locates every [Flame] file on disk, removes it, and subsequently overwrites the disk with random characters to prevent anyone from obtaining information about the infection," the Symantec researchers said. "This component contains a routine to generate random characters to use in the overwriting operation. It tries to leave no traces of the infection behind."
Deleting a file in Windows does not remove its actual data from the physical hard disk. It only flags the hard disk sectors occupied by that file as available for the operating system to rewrite.
However, since there is no way to predict when the operating system will actually overwrite those sectors, the deleted file, or portions of it, can be recovered with special data recovery tools -- at least for a limited period of time.
According to Aleks Gostev, chief security expert with Kaspersky Lab's global research & analysis team, the overwriting of file data with meaningless characters happens before the Flame files get deleted by browse32.ocx, not after as Symantec suggested. However, the goal is the same -- eliminating all traces of the malware and making forensic analysis harder, he said via email.
Last week, Kaspersky's researchers said that they discovered Flame while investigating a series of data loss incidents in Iran that could have been caused by a piece of malware. However, no evidence that links Flame to those attacks has been found yet.
Kaspersky's researchers didn't exclude the possibility that a yet-to-be-identified Flame component was responsible for the data destruction in Iran, but if such a component exists, it's probably not browse32.ocx.
"Browse32 does not overwrite the hard disk the way Wiper [the mystery malware] did it," Gostev said. "It wipes only files related to Flame."
- DOJ's charges against China reframe security, surveillance debate
- Hacker indictments against China's military unlikely to change anything
- U.S. to formally accuse Chinese military of hacking
- Cyberattacks could paralyze U.S., former defense chief warns
- The NSA blame game: Singling out RSA diverts attention from others
- Jury still out on FISA court
- Suspected China-based hackers 'Comment Crew' rises again
- Chinese hackers master the art of lying in wait
- Spy court OK'd all U.S. wiretap requests it received in 2012
- Groups denounce FBI plan to require Internet backdoors for wiretaps
- Transforming Information Security: Future-Proofing Processes This report provides a valuable set of recommendations from 19 of the world'd leading security officers to help organizations build security strategies for...
- The Evolution of Corporate Cyberthreats Cybercriminals are creating and deploying new threats every day that are more destructive than ever before. While you may have more people devoted...
- 3 Questions to Ask Your DNS Host about Lowering DDoS Risks Neustar has had wide-ranging conversations with clients wanting to know how they can optimize protection as DDoS attacks increase in frequency and size.
- The Danger Deepens: 2014 Neustar Annual DDoS Attacks and Impact Report This report compares DDoS findings from 2013 to 2012, based on a survey of 440 North American companies, including 139 businesses delivering technology...
- Establish Cyber Resiliency: Developing a Continuous Response Architecture Many enterprises fail to proactively prepare the battlefield for a data breach by only leveraging outdated techniques that focus on the perimeter or...
- An Incident Response Playbook: From Monitoring to Operations As cyber-attacks grow more sophisticated, many organizations are investing more into incident detection and response capabilities. In this webcast, learn how to develop... All Cybercrime and Hacking White Papers | Webcasts