Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Attacks/Breaches

Gumblar Botnet Resurges

Reactivation of Gumblar.cn domain could have ripple effect, researchers say

Gumblar, a botnet that emerged as one of the Internet's largest earlier this year, is back, researchers said yesterday.

According to researchers at ScanSafe, a new iFrame injection is pointing once again to gumblar.cn -- the malware domain that originally earned Gumblar its name.

"The domain's reactivation occurred less than 24 hours ago, but it has ramifications that could stretch back for months," said ScanSafe researcher Gregg Conklin, in a blog. "Any sites compromised in the May Gumblar attacks that were not yet cleaned up (unfortunately an all-to-common occurrence) could now start becoming vectors of Gumblar infection once again. This is in addition to new compromises pointing to the newly-activated gumblar.cn and the already very active Gumblar compromises which are using compromised websites as malware hosts."

The Gumblar infection manifests in two ways, ScanSafe says. In some cases, the compromised sites may act as actual malware hosts. In other cases, the compromised sites are injected with iFrames that point to those malware hosts.

"In a typical Web malware outbreak, there are only a few malware hosts," Scansafe says. "But because the Gumblar attackers have this botnet of backdoored Websites at their disposal, there are now thousands of malware hosts. This makes stemming the flow of the attacks (i.e., shutting down the hosts) nearly impossible."

In October, 28.8 percent of all ScanSafe Web malware blocks were the result of the latest Gumblar attacks -- double the amount observed in the May outbreak, ScanSafe says. "The latest run of Gumblar has been highly successful for the attackers, all because the malware itself is being hosted on thousands of other compromised sites," Conklin says.

Have a comment on this story? Please click "Discuss" 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 Reading.com, 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
Comments
Newest First  |  Oldest First  |  Threaded View
Commentary
Ransomware Is Not the Problem
Adam Shostack, Consultant, Entrepreneur, Technologist, Game Designer,  6/9/2021
Edge-DRsplash-11-edge-ask-the-experts
How Can I Test the Security of My Home-Office Employees' Routers?
John Bock, Senior Research Scientist,  6/7/2021
News
New Ransomware Group Claiming Connection to REvil Gang Surfaces
Jai Vijayan, Contributing Writer,  6/10/2021
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
The State of Cybersecurity Incident Response
In this report learn how enterprises are building their incident response teams and processes, how they research potential compromises, how they respond to new breaches, and what tools and processes they use to remediate problems and improve their cyber defenses for the future.
Flash Poll
How Enterprises are Developing Secure Applications
How Enterprises are Developing Secure Applications
Recent breaches of third-party apps are driving many organizations to think harder about the security of their off-the-shelf software as they continue to move left in secure software development practices.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2021-31494
PUBLISHED: 2021-06-15
This vulnerability allows remote attackers to execute arbitrary code on affected installations of OpenText Brava! Desktop 16.6.3.84. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within th...
CVE-2021-31495
PUBLISHED: 2021-06-15
This vulnerability allows remote attackers to execute arbitrary code on affected installations of OpenText Brava! Desktop 16.6.3.84. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within th...
CVE-2021-31496
PUBLISHED: 2021-06-15
This vulnerability allows remote attackers to execute arbitrary code on affected installations of OpenText Brava! Desktop 16.6.3.84. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within th...
CVE-2021-31497
PUBLISHED: 2021-06-15
This vulnerability allows remote attackers to execute arbitrary code on affected installations of OpenText Brava! Desktop 16.6.3.84. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within th...
CVE-2021-31498
PUBLISHED: 2021-06-15
This vulnerability allows remote attackers to disclose sensitive information on affected installations of OpenText Brava! Desktop 16.6.3.84. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists w...