The hackers who broke into EMC's RSA Security division last March used the same attack code to try to break into several other companies, including two US national security organisations, according to data provided by the VirusTotal website.
"According to our data, RSA was just one of the targets," said Bernardo Quintero, the founder of malware analysis site VirusTotal. Attackers "used the same malware to try to penetrate other networks," he added.
VirusTotal is a popular site with security professionals who use it to get a quick industry consensus take on suspicious files. It runs any file through a battery of antivirus scanning engines and spits out a report within minutes. Someone at EMC used the service on March 19 to analyse an email message that contained that spearphishing attack that was used to break into RSA.
But according to Quintero, before the attack was publicly disclosed in mid-March, the same maliciously encoded Excel spreadsheet had already been uploaded to VirusTotal 16 times from 15 different sources. The first was on March 4 - the day after the message was sent to RSA - and the malware was detected by none of the site's 42 antivirus engines.
Because it relies on anonymous submissions, VirusTotal won't say who uploaded the documents. But according to Quintero's analysis, two of the targets were entities related to US national security.
Buried in the metadata of the attack files is another clue: a sign that whoever created the attack used a Chinese language version of Excel - Windows Simplified Chinese (PRC, Singapore). The attackers could have deliberately changed the file's settings to make it look like it came from China, but Quintero believes it "was a simple oversight" on the part of the hackers.
It would be natural for the person who wrote the RSA attack code to try to use it as much as possible before it was discovered and patched. Here the code was embedded in Excel documents, but the flaw it exploited when the documents were opened actually lay in Adobe's Flash Player.
Adobe learned of the issue on March 9, when a "partner in the security community" noticed the attack code at an undisclosed customer site, said Weibke Lips, an Adobe spokeswoman. Before Adobe released its first advisory, a second customer - not RSA - reported the attack, Lips said.
The RSA hackers broke in using a basic social engineering attack. They sent an email that looked like it came from an RSA partner, online recruiting firm Beyond.com, with the simple message, "I forward this file to you for review. Please open and view it." That file was named 2011 Recruitment plan.xls. Quintero says that a second file name - survey-questions_2011.xls - was also used by the hackers.
In a post written shortly after the Adobe flaw was first disclosed, the Contagio Malware Dump blog listed four different Excel files that were being used in attacks, including a Nuclear Radiation Exposure And Vulnerability Matrix.xls file that was doctored to look as though it came from the US Nuclear Regulatory Commission.
It's not clear who this file was sent to, but in the March 17 spearphishing email also published on the blog, the attackers seem to be going after someone who would have taken an interest in the recent Japan earthquake. With the subject line, "Japan Nuclear Radiation Leakage and Vulnerability Analysis," the email states, simply, "The team has poured in heart and full dedication into this. Would be grateful if you appreciate it."
VirusTotal's findings offer clues but no answers to the attack on RSA, which was ultimately seen as a stepping stone to further attacks on defence contractors Lockheed Martin, L-3 and Northrop Grumman.
It's possible that the hackers who developed the attack used on RSA shopped around their attack code to other groups with other goals. Once a previously unknown zero-day flaw is found, there's a lot of pressure to exploit it as much as possible before it is discovered and then patched, said Alex Stamos, a founder of NCC Group's iSec Partners. So it's "not shocking at all" to find that other companies were targeted with the same attack code, he said.
McAfee's research shows that other defense organisations were targeted with the attack, although not necessarily at the same time as the RSA incident, said Dmitri Alperovitch, McAfee's vice president of threat research. "After that vulnerability became known a lot of people started leveraging it, and that continued through April," he said.