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.

Cloud

6/8/2016
03:30 PM
Connect Directly
Twitter
RSS
E-Mail
50%
50%

Fast Flux Taken To The Next Level With Zbot Botnet

Zbot's success rests largely on its makers' ability to take advantage of fast-flux network infrastructure.

As attackers seek to maximize their profits and minimize downtime, fast flux networks have grown into a pivotal technique for bad guys seeking to evade detection. And according to a new report out today from RiskAnalytics, there's perhaps no better example of the evolution of fast fluxing techniques than the architecture that's arisen through the highly successful Zbot botnet.

"Much like businesses, it's all about uptime and making money. For the criminals, this is the evolution of that," says Wayne Crowder, director of threat intelligence for RiskAnalytics, referring to rise of Zbot in the underground economy based on its effective fast-flux techniques.

"It's harder to take down, it's harder to track and to control, and they're all about using this to provide uptime and resources for the criminal services sold, ensuring a higher-tier service in the criminal underground," he says.

Fast fluxing is a means of upping the frustration of security team's whack-a-mole hunt for malicious traffic by hiding the infrastructure that hosts malware, phishing, and other nasty sites on a constantly-changing rotation of compromised hosts acting as proxies. The technique has been around for years, but Zbot has taken it to the next level in the advancement of techniques and the scope at which it runs.

"Participating domains return a set of 10 IP addresses for each query with a varying DNS cache time-to-live (TTL) of less than 150 seconds, forcing the addresses to be refreshed after no more than two and a half minutes," explained Crowder and his report co-author Noah Dunker, director of security labs for RiskAnalytics. "Over time, hundreds or thousands of IP addresses are used. This technique is designed to bypass IP address blocking solutions while still maintaining the advantages of a highly-available network." 

One of the techniques that makes Zbot so notable is its use of double fast-fluxing, Dunker says.

"I think what really caught my attention here was that not only did we have fast flux, but we had double flux, which is where the authoritative DNS for the botnet is hosted inside the botnet itself and it is also a moving target," he says.

Additionally, Zbot stands out in its makers' business acumen and their ability to leverage these techniques to build out its level of services, making it a nexus of crimeware campaigns. 

"We weren’t dealing with a single hostname or a tiny group of hostnames or the same kind of behavior on this fast flux botnet," says Dunker. "We were running into a very diverse list of products running on this."

The laundry list included banking Trojans, carder sites, ransomware, spam sent from within the network, click fraud, and more. Overall, Dunker says the takeaway for security professionals is that this is yet another sign of how the criminals continue to hone their trade craft.

"One of the big takeaways is that the criminals are not relying on the old guard of bulletproof hosting providers overseas," he says. "They’re building their own networks from scratch with these botnet tools."

What this means for infosec practices is that not only are the networks resilient, but it is lowering the effectiveness of a lot of endpoint antivirus solutions.

"We highlighted some really low detection rates [in the report] in fact some [Zbot] samples were completely undetected on the first day that we saw the samples. And these are things that pull down multiple different types of malware and then install them on the infected computer," he says.

Related Content:

Ericka Chickowski specializes in coverage of information technology and business innovation. She has focused on information security for the better part of a decade and regularly writes about the security industry as a contributor to Dark Reading.  View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Why Cyber-Risk Is a C-Suite Issue
Marc Wilczek, Digital Strategist & CIO Advisor,  11/12/2019
DevSecOps: The Answer to the Cloud Security Skills Gap
Lamont Orange, Chief Information Security Officer at Netskope,  11/15/2019
Unreasonable Security Best Practices vs. Good Risk Management
Jack Freund, Director, Risk Science at RiskLens,  11/13/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
Navigating the Deluge of Security Data
In this Tech Digest, Dark Reading shares the experiences of some top security practitioners as they navigate volumes of security data. We examine some examples of how enterprises can cull this data to find the clues they need.
Flash Poll
Rethinking Enterprise Data Defense
Rethinking Enterprise Data Defense
Frustrated with recurring intrusions and breaches, cybersecurity professionals are questioning some of the industrys conventional wisdom. Heres a look at what theyre thinking about.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-19040
PUBLISHED: 2019-11-17
KairosDB through 1.2.2 has XSS in view.html because of showErrorMessage in js/graph.js, as demonstrated by view.html?q= with a '"sampling":{"value":"<script>' substring.
CVE-2019-19041
PUBLISHED: 2019-11-17
An issue was discovered in Xorux Lpar2RRD 6.11 and Stor2RRD 2.61, as distributed in Xorux 2.41. They do not correctly verify the integrity of an upgrade package before processing it. As a result, official upgrade packages can be modified to inject an arbitrary Bash script that will be executed by th...
CVE-2019-19012
PUBLISHED: 2019-11-17
An integer overflow in the search_in_range function in regexec.c in Oniguruma 6.x before 6.9.4_rc2 leads to an out-of-bounds read, in which the offset of this read is under the control of an attacker. (This only affects the 32-bit compiled version). Remote attackers can cause a denial-of-service or ...
CVE-2019-19022
PUBLISHED: 2019-11-17
iTerm2 through 3.3.6 has potentially insufficient documentation about the presence of search history in com.googlecode.iterm2.plist, which might allow remote attackers to obtain sensitive information, as demonstrated by searching for the NoSyncSearchHistory string in .plist files within public Git r...
CVE-2019-19035
PUBLISHED: 2019-11-17
jhead 3.03 is affected by: heap-based buffer over-read. The impact is: Denial of service. The component is: ReadJpegSections and process_SOFn in jpgfile.c. The attack vector is: Open a specially crafted JPEG file.