Researchers found samples of malicious PDF files exploiting the recently disclosed Adobe zero-day vulnerability that were sent to defense contractors and other organizations.
Attacks exploiting an Adobe
Reader zero-day vulnerability appear to have targeted defense contractors and
other organizations, according to security researchers.
Adobe issued a security
advisory on Dec. 6 warning Adobe Reader and Acrobat users of a critical
vulnerability in how the programs accessed PDF files. The flaw was also being
exploited in the wild against Adobe
Reader 9.x users on Windows
, Adobe said.
Symantec researchers found
that attack emails with malicious PDF files that exploited the flaw were sent
to telecommunications and chemical companies as well as defense contractors,
Joshua Talbot, security intelligence manager of Symantec Security Response,
The emails had been spoofed
to look like they were sent from agencies and organizations that were familiar
to the recipients, he said. Symantec security researchers found attack emails
from Nov. 1 and Nov. 5 that exploited the vulnerability, Stephen Doherty, a
security response engineer at Symantec, wrote on the Symantec
Security Response blog
Attackers used "social
engineering to trick users into opening the file," Talbot said.
In a separate analysis,
independent security researcher Brandon Dixon
malicious PDF file masquerading as an employee-satisfaction survey for ManTech,
a defense contractor affiliated with Lockheed Martin, Dixon wrote on 9B+ blog
Dec. 7. The file was found in PDF X-Ray
a project run by Dixon to capture and detect malicious PDF files circulating on
Lockheed Martin and the
Defense Security Information Exchange were credited for bringing the
vulnerability to Adobe's attention, according to the security advisory. The
DSIE is a group of major defense contractors that are part of the Defense
Industrial Base and share information about computer attacks with each other.
DIB members include Boeing, General Dynamics, Lockheed Martin, Northrup
Grumman, Pratt & Whitney and Raytheon.
The attackers were sophisticated,
customizing the attack for each victim, as they crafted different PDF files and
attack emails to specifically target each organization, Talbot said.
"Someone in the communications industry is likely to receive a different
email and PDF file than someone in a manufacturing company would," he
Even though the PDF files
were different, both Symantec and Dixon's analysis showed that when the files
were opened in Reader 9.4.6, the vulnerability was exploited to download and
infect computers with malware Symantec identified as Backdoor.Sykipot. The file
before executing the malicious code, Dixon said.
The attachment found by
Symantec claimed to be an updated contract guide for contractors for fiscal
year 2012, according to the screenshot on the Symantec blog. "The new
guide contains update information of ___ policy on contract award
process," the email said. The targeted emails appear to have included the
name of the organization the contractor would be affiliated with.
Dixon's ManTech survey
caused the application to crash and then open a new document containing
questions such as "Overall, how satisfied are you with MANTECH as an
employer?" and ratings on "MANTECH's communication and planning."
Backdoor.Sykipot is not a
widespread piece of malware, but it was used as part of an attack last year
that exploited a zero-day vulnerability in Internet Explorer, according to
Talbot. "Given that the methodology is similar and it's not a widely used
attack tool, chances were high" that the attacks were related, he said.
The attack was more
sophisticated than general attacks since there is more effort required to find
and exploit the zero-day, according to Talbot.
Adobe said in its advisory
that it will patch the Windows versions of Reader and Acrobat 9.x by the end of
next week, and has promised updates for Reader and Acrobat 9.x to Mac and Unix
users, and to Reader and Acrobat 10.x for all platforms during the next
quarterly scheduled update in January.