08:04 AM
Tim Wilson
Tim Wilson
Quick Hits

GameOver Zeus Authors Try A New Tactic: Encryption

Authors of malicious GameOver Zeus exploit dodge detection with new encryption scheme

The authors of the GameOver Zeus malware are taking a new approach to avoiding detection: encryption.

According to a blog posted Sunday by researchers at Malcovery Security, the new approach could enable the malware to escape conventional security defenses.

Gary Warner, co-founder and CTO at Malcovery, writes that GameOver Zeus' authors are "encrypting their EXE file so that as it passes through your firewall, Web filters, network intrusion detection systems, and any other defenses you may have in place, it is doing so as a non-executable '.ENC' file."

While antivirus tools and other products have recently improved their ability to detect and block the dangerous Zeus variant, the encrypted attack was not detected by any of the 50 products used by VirusTotal, according to the blog.

"Why? Well, because technically, [the encrypted ENC file] isn't malware," Warner writes. "It doesn't actually execute! All Windows EXE files start with the bytes 'MZ.' These files start with 'ZZP.' They aren't executable, so how could they be malware? Except they are."

In the blog, Warner gives many examples that show how the campaign works and how the malware is delivered. He also offers a bit of advice.

"If you are in charge of network security for your enterprise, you may want to check your logs to see how many .ENC files have been downloaded recently," the blog warns.

Have a comment on this story? Please click "Add a Comment" below. If you'd like to contact Dark Reading's editors directly, send us a message. Tim Wilson is Editor in Chief and co-founder of Dark, UBM Tech's online community for information security professionals. He is responsible for managing the site, assigning and editing content, and writing breaking news stories. Wilson has been recognized as one ... View Full Bio

Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
White Papers
Current Issue
Dark Reading Tech Digest September 7, 2015
Some security flaws go beyond simple app vulnerabilities. Have you checked for these?
Flash Poll
Threat Intel Today
Threat Intel Today
The 397 respondents to our new survey buy into using intel to stay ahead of attackers: 85% say threat intelligence plays some role in their IT security strategies, and many of them subscribe to two or more third-party feeds; 10% leverage five or more.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
Published: 2015-10-05
system/session/drivers/cookie.php in Anchor CMS 0.9.x allows remote attackers to conduct PHP object injection attacks and execute arbitrary PHP code via a crafted serialized object in a cookie.

Published: 2015-10-05
The Secure Meeting (Pulse Collaboration) in Pulse Connect Secure (formerly Juniper Junos Pulse) before 7.1R22.1, 7.4, 8.0 before 8.0R11, and 8.1 before 8.1R3 provides different messages for attempts to join a meeting depending on the status of the meeting, which allows remote attackers to enumerate ...

Published: 2015-10-05
The Secure Meeting (Pulse Collaboration) in Pulse Connect Secure (formerly Juniper Junos Pulse) before 7.1R22.1, 7.4, 8.0 before 8.0R11, and 8.1 before 8.1R3 allows remote authenticated users to bypass intended access restrictions and log into arbitrary meetings by leveraging a meeting id and meetin...

Published: 2015-10-05
Heap-based buffer overflow in the parse_string function in libs/esl/src/esl_json.c in FreeSWITCH before 1.4.23 and 1.6.x before 1.6.2 allows remote attackers to execute arbitrary code via a trailing \u in a json string to cJSON_Parse.

Published: 2015-10-05
Unrestricted file upload in GLPI before 0.85.3 allows remote authenticated users to execute arbitrary code by adding a file with an executable extension as an attachment to a new ticket, then accessing it via a direct request to the file in files/_tmp/.

Dark Reading Radio
Archived Dark Reading Radio
What can the information security industry do to solve the IoT security problem? Learn more and join the conversation on the next episode of Dark Reading Radio.