A sanctioned security test of a bank's computer systems had some unexpected consequences last week, leading the federal agency that oversees U.S. credit unions to issue a fraud alert.
On last Tuesday, the National Credit Union Administration (NCUA) warned all federally insured credit unions of a bogus letter that an unnamed credit union had received along with two CDs. The bogus letter claimed that the CDs contained NCUA anti-fraud training materials, but in its fraud alert, NCUA warned that running the CDs “could result in a possible security breach to your computer system, or have other adverse consequences.”
Only it turned out that the CDs were not sent by fraudsters. They were sent by employees of MicroSolved, a Columbus, Ohio, security testing company. “It was a part of some social engineering we were doing in a fully sanctioned penetration test,” said MicroSolved CEO Brent Huston in an e-mail message.
Companies like MicroSolved are routinely hired to independently test the security of corporations and government agencies.
Penetration testers often use so-called social engineering techniques as part of their security assessment work. With social engineering, the attacker typically pretends to be a legitimate partner or co-worker in order to trick employees into compromising their computer systems or divulging sensitive information. “Social engineering exercises are a part of most of our assessments,” Huston said.
NCUA spokesman John McKechnie did not have much to say about his organization's alert. In a brief e-mail Thursday, he wrote “at this point, it appears that this is an isolated event.”
Even if the threat that prompted the NCUA warning was not based on a real attack, the warning contains good information, according to Johannes Ullrich, chief research officer at the SANS Institute, a security training group. “It's a good lesson,” he said. According to him, all of the parties in the exercise acted pretty much as they should have. The bank “reported it to their controlling agency, who then put out this alert based on it.”
California Credit Union League Director of Research and Information, Rita Fillingane, said the alert was still useful, even if it wasn't based on an actual criminal act.” In the future something like this could come down the pike,” she said.
Still, Ullrich said he is not aware of any cases where bogus CDs were actually used to compromise a computer network.
He said he was initially extremely interested when he saw the initial NCUA warning. “I thought, 'Finally this is in the wild, because I've only seen it in pen tests before.'