Attacks/Breaches
12/4/2012
05:05 PM
Connect Directly
Google+
Twitter
RSS
E-Mail
50%
50%
Repost This

'Gameover Zeus' Gang Launches New Attacks

Campaign includes rigged emails spoofing major U.S. banks and offering 'secure email' exchange with banking customers

The cybercrime group behind the Gameover Zeus Trojan that steals online banking creds and credit card numbers is waging a massive malicious email campaign that enlists the massive Cutwail spamming botnet to blast its emails.

Millions of emails -- many of which pose as coming from major U.S. banks -- have been spammed out in recent weeks, according to Dell SecureWorks' Counter Threat Unit. The phony but convincing-looking emails appeal to a more security-minded banking customer: "You have received a new encrypted message or a secure message from [XYZ] Bank," one of the email campaigns says, noting that the bank has set up a secure email exchange for its customers as a way to allay privacy and security concerns.

The message includes an infected attachment that the "bank" requires for download and registration to the supposed secure email system. Once downloaded, it executes the pony downloader Trojan that installs Gameover and steals online banking credentials, credit card account numbers, and other information.

Another email campaign claims the recipient has received a fax, scan, or voicemail, and includes a "free program" for retrieving the message -- but, of course, the attachment installs the malware.

The Gameover gang, unlike some cybercrime groups, doesn't lease or sell its malware or services. It's a closed operation that, instead, sometimes contracts resources such as the Cutwail botnet to transport its attacks. More than half of the Top 20 Fortune 500 firms were infected with the Trojan as of this summer, according to SecureWorks, which in July published a report on Gameover

"This particular group has found a combination of malware, tactics, and procedures that leads to success for them. They will continue to follow the same process [of working this way]," says Jon Ramsey, CTO of Dell SecureWorks. "The malware they use is a private version of theirs, and they don't sell it on the black market. They feel there's more of an upside financially in keeping it private."

Ramsey says the gang has had plenty of success creating large botnets for both sending more malicious spam and conducting distributed denial-of-service attacks. They're using a dual-botnet sort of model with Cutwail transporting the spam, and subsequently infected Gameover bots spreading their infections and doing the Gameover botnet operators' bidding.

About 678,205 machines were infected with Gameover Zeus in August, according to SecureWorks, and it's the biggest botnet targeting financial institutions today. Fourteen of the 20 top Fortune 500 firms are infected, including financial services firms, defense contractors, government agencies, law enforcement, military, and universities.

The peer-to-peer Gameover botnet was structured to deter disruption and to make attribution more difficult. Even so, peer-to-peer botnets are easier to "poison" by using phony peers that allow researchers to sinkhole traffic, according to Brett Stone-Gross, who has closely studied Gameover.

"The P2P ZeuS crew receives considerable support from the products and services offered by the underground community, who collectively fulfill vital functions to plan and execute a large successful cybercriminal operation. Moreover, the large number of compromised personal computers and web servers provide a robust and low cost infrastructure for a variety of malicious activities," Stone-Gross wrote in his report.

[Trade-offs are a fact of life for network defenders, but attackers have to abide them as well. See The Attacker's Trade-Off: Stealth Versus Resilience.]

Cutwail, one of the world's largest botnets, to date contains around 500,000 or so bots, according to SecureWorks data.

Researchers at LookingGlass Cyber Solutions say the top 10 countries infected by the Cutwail botnet, in order, are: India, Iran, China, Vietnam, Ukraine, Kazakhstan, Belarus, the U.S., South Korea, and Brazil.

"We saw 43,332 unique hosts infected with Cutwail on December 3, 2012," says Jason Lewis, chief scientist with LookingGlass. Overall, the researchers saw some 203,117 bots sending spam -- from botnets including Cutwail, Asprox, Festi, and Kelihos.

"About 3,000 hosts had multiple infections," Lewis says.

Have a comment on this story? Please click "Add Your Comment" below. If you'd like to contact Dark Reading's editors directly, send us a message.

Kelly Jackson Higgins is Senior Editor at DarkReading.com. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise Magazine, ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
DarkReadingTim
50%
50%
DarkReadingTim,
User Rank: Strategist
12/5/2012 | 2:39:04 PM
re: 'Gameover Zeus' Gang Launches New Attacks
Attacks on banks continue to be a favorite for cybercriminals. I'll be posting a story on a new attack on European banks later today.-á
-- Tim Wilson, editor, Dark Reading
Register for Dark Reading Newsletters
White Papers
Cartoon
Current Issue
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2012-3946
Published: 2014-04-24
Cisco IOS before 15.3(2)S allows remote attackers to bypass interface ACL restrictions in opportunistic circumstances by sending IPv6 packets in an unspecified scenario in which expected packet drops do not occur for "a small percentage" of the packets, aka Bug ID CSCty73682.

CVE-2012-5723
Published: 2014-04-24
Cisco ASR 1000 devices with software before 3.8S, when BDI routing is enabled, allow remote attackers to cause a denial of service (device reload) via crafted (1) broadcast or (2) multicast ICMP packets with fragmentation, aka Bug ID CSCub55948.

CVE-2013-6738
Published: 2014-04-24
Cross-site scripting (XSS) vulnerability in IBM SmartCloud Analytics Log Analysis 1.1 and 1.2 before 1.2.0.0-CSI-SCALA-IF0003 allows remote attackers to inject arbitrary web script or HTML via an invalid query parameter in a response from an OAuth authorization endpoint.

CVE-2014-2391
Published: 2014-04-24
The password recovery service in Open-Xchange AppSuite before 7.2.2-rev20, 7.4.1 before 7.4.1-rev11, and 7.4.2 before 7.4.2-rev13 makes an improper decision about the sensitivity of a string representing a previously used but currently invalid password, which allows remote attackers to obtain potent...

CVE-2014-2392
Published: 2014-04-24
The E-Mail autoconfiguration feature in Open-Xchange AppSuite before 7.2.2-rev20, 7.4.1 before 7.4.1-rev11, and 7.4.2 before 7.4.2-rev13 places a password in a GET request, which allows remote attackers to obtain sensitive information by reading (1) web-server access logs, (2) web-server Referer log...

Best of the Web