LinkedIn Hack Demonstrates Ease of Impersonation

LAS VEGAS -- Black Hat USA and DefCon 16 -- A pair of researchers successfully impersonated security icon Marcus Ranum on the social networking site LinkedIn recently, even fooling Ranum’s sister into “friending” the phony Ranum profile.

The exercise, which researchers Shawn Moyer and Nathan Hamiel demonstrated here at both hacker conferences last week, was to show just how easy it really is to impersonate someone on a social networking site. The lack of authentication and validation of social networking personae, as well as a culture of often-blind trust, was the perfect recipe for a case of an online phony identity, according to Moyer and Hamiel, who showed off this and other simple hacks on popular social networking sites in their "Satan is On My Friends List: Attacking Social Networks" presentation.

Ranum -- who doesn't have a LinkedIn profile -- was on board with the experiment, so the researchers culled press releases, bios, articles, and his photo off the Web and built the phony Ranum profile on the social networking site. “We then built legitimacy quickly. There’s this weird underbelly of users that accept invitations from anybody for no reason. In social networks, friends are currency,” Moyer said. Some of these are the so-called “open networkers,” who are members of most every LinkedIn group, so Moyer and Hamiel did a Google search for several of these users to which they sent invites to link to Ranum.

They had 42 connections to the phony Ranum profile within 12 hours, and after joining several security networking communities to build in more credibility (CISO: Meaningful Metrics, ISACA, Executive Suite, Enterprise Security, Security Leaders, and BlackHat), they got connection requests from the CSO of a security firm, from a former CSO of a Fortune 100 company, and then, from Ranum’s sister, who also fell for the ploy.

The researchers said that if their phony profile had contained a link to another Website or to a new application, they would have had more success than a typical phishing attack.

LinkedIn, MySpace, Facebook, and HighFive are all vulnerable in some way because they’re open social networking sites. They are susceptible to threats from voluntary mashups, as well as to attacks via custom applications that members can write for their sites and for other users to deploy, the researchers said.

“Who needs vulns when you have open APIs?” Hamiel said. “You write once and own anyone. One of the cool things is that it’s centrally located... You can go rogue when you get installs. It’s malware-as-a-service.”

— Kelly Jackson Higgins, Senior Editor, Dark Reading