Attackers continue to find new manners to game social networking sites into becoming their devices for doing everything from prospecting for victims to distributing malware, and researchers at Symantec are highlighting another emerging technique that manipulates Web 2.0 — the use of the sites as command centers for backdoor Trojans.
In the latest reported instance, attackers are using the Google Groups message boards to integrate Trojan commands into valid URLs, the first example that the experts have seen of newsgroups being abused in such a fashion.
The activity is related specifically to the manipulation of a back door Trojan that the company has dubbed Trojan.Grups.
The Trojan itself is pretty simple, noted Symantec researcher Gavin O. Gorman in a related blog post. Trojan.Grups is distributed as a DLL, and when executed will log onto a specific account, he said.
“Trojan distribution via newsgroups is relatively common, but this is the first instance of newsgroup C&C usage that Symantec has detected,” the expert reported.
Of course, Google itself has nothing to do with the availability of the attack method as the schemers are taking advantage of the site’s legitimate communications functionality.
Gorman highlighted the fact that because the newsgroup can store both static “pages” and postings, when the attack requests a page from a private newsgroup, “escape2sun,” merely runs its course as designed, allowing its controllers to anonymously distribute commands in the process.
However, while the technique does help attackers hide themselves, it does make the threat somewhat easier to spot, Gorman said.
“It is an effective technique for anonymously issuing commands; however, it does have some negative aspects for the attacker. Since every response is stored as a posting in the newsgroup, it was possible for Symantec to track the activity of the Trojan in detail,” he said.
The sites “version control” feature can also be used to monitor for modifications to the involved page(s), allowing researchers to decrypt commands and observe the Trojan’s behavior, the researcher noted.
An even more useful feature of the newsgroup is the version control incorporated into pages. Approximately 34 page modifications can be observed over a ten-month period. By decrypting the recorded page edits, the evolution of commands over time can be clearly observed.
After doing so, Gorman said it appears that the involved attack is likely just serving as a sort of feeler, used to do information gathering about potential targets. The expert said that the threat also appears to have emanated from China.
And while it may only be a sort of a test at this point, “such a Trojan could potentially have been developed for targeted corporate espionage where anonymity and discretion are priorities.”
Social networking sites aren’t going away anytime soon, in fact they only seem to continue to proliferate. However, both their operators and customers alike will seemingly need to buckle down and find ways to prevent such open and sophisticated abuse by attackers if the sites aren’t to be undermined by their vulnerability.
The big question remains how to do so without detracting from their original purpose – open and unfettered communications.
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Matt Hines has been following the IT industry for over a decade as a reporter and blogger, and has been specifically focused on the security space since 2003, including a previous stint writing for eWeek and contributing to the Security Watch blog. Hines is currently employed as marketing communications manager at Core Security Technologies, a Boston-based maker of security testing software. The views expressed herein do not necessarily represent the views of Core Security, and neither the company, nor its products and services will be actively discussed in the blog. Please send news, research or tips to SecurityWatchBlog@gmail.com.
