Here's how the attack succeeded, according to what RSA reported Friday: The attacker sent two small batches of emails with "2011 Recruitment Plan" as the subject line to two small groups of EMC employees with an Excel spreadsheet attached, which at least some recipients executed. But the spreadsheet included an embedded Flash file that executed malicious code via a zero-day vulnerability, enabling the attacker to gain full access to the PC and install software to more easily control it remotely.
"The attacker in this case installed a customized remote administration tool known as Poison Ivy RAT variant," said Uri Rivner, head of new technologies in the consumer identity protection group at RSA, in a Friday blog post.
Rather than receiving commands from a control server, tools such as Poison Ivy pull commands from an external server. "This connectivity method makes them more difficult to detect, as the PC reaches out to the command and control rather than the other way around," he said. Poison Ivy has been used in numerous other attacks, including the Operation Aurora attack against Google in late 2009.
After penetrating EMC's network, the attacker targeted credentials for people with access to high-value information, aggregated that information, and then exported it via FTP to an external Web site, where it was downloaded and then erased -- evidence of the attacker hiding his or her tracks.
Rivner emphasized that RSA had been hit by an advanced persistent threat (APT) attack. "One cannot stress enough the point about APTs being, first and foremost, a new attack doctrine built to circumvent the existing perimeter and endpoint defenses," he said.
But many security experts have labeled "APT," at least in this case, as an exercise in spin, noting that threats that blend multiple attack modes, including social engineering, have been around for years.
"There is very little in this attack that is particularly sophisticated. The big question is, what are the defenses that would have prevented or reduced the impact of this attack?" said Rick Wanner at the SANS Internet Storm Center in an online post.
As noted, RSA's Rivnerk also offered no additional information on exactly what the attackers stole, saying only that "RSA made it clear that certain information was extracted."
That lack of specificity from RSA left many SecurID users preparing for the worst, which is that their two-factor authentication system can't be trusted.
Adobe has since patched the vulnerability exploited by the RSA attacker.