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.

Vulnerabilities / Threats

6/27/2016
04:00 PM
Connect Directly
Twitter
RSS
E-Mail
50%
50%

Cerber Strikes With Office 365 Zero-Day Attacks

Ransomware variant continues its success through chameleon-like reinvention.

Variants of Cerber ransomware are pivoting yet again, this time targeting Office 365 email users with a zero-day attack that security experts say likely impacted millions of business users last week. According to a new report from cloud security provider Avanan today, Cerber changed up its attack M.O., shifting gears to utilize a zero-day attack that bypasses Office 365's built-in security tools and hammering Office 365 email users with a phishing campaign.

While Avanan couldn't measure the infection rate, it said that the campaign hit approximately 57 percent of organizations that it services that use Office 365. It said that the attack was detected by customers using Check Point's SandBlast Zero-Day Protection on the Avanan platform, with most traditional antiviruses not detecting the cloud email attack when it was initially found.

 “Many users of cloud email programs believe they 'outsourced' everything to Microsoft or Google, including security,” explains Gil Friedrich, CEO of Avanan. “The reality is that hackers first make sure their malware bypasses major cloud email providers' security measures, and so most new malware goes through cloud email programs undetected."

Like many successful ransomware variants, Cerber has maintained its high infection rates through constant reinvention and innovation. First cropping up at the end of February this year, Cerber initially made headway distributed through malvertising that was driven by the Magnituted and Nuclear exploit kits' use of Flash zero-day exploits, according to Trend Micro and FireEye researchers.  

By May, Cerber was seen delivered frequently by Dridex in spam campaigns that were seeking to drop the malware via malicious Microsoft Office documents taking advantage of macro vulnerability exploits, according to FireEye. And earlier this month, researchers with Invincea warned that Cerber was utilizing a polymorphic "hash factory" technique to change payloads on the fly as often as every 15 seconds in order to evade signature-based detection.

"When we tried to duplicate the download for this variant, we noticed that the hash we received from the payload delivery server had a different hash than the one in the event above. When we downloaded it a third time, there was yet another hash," wrote Pat Belcher with Invincea about their findings. "Fifteen seconds later, there was another, and then another. In all we downloaded over 40 uniquely hashed Cerber payloads – all with different hashes. It appeared we were dealing with a server-side malware factory."

Among all of the derivations, one unique factor seems to be threaded through all of the Cerber attacks.  The ransomware is designed to deliver its ransom demand via a spoken voice note that plays when a victim tries to open a file.

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
 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
COVID-19: Latest Security News & Commentary
Dark Reading Staff 8/3/2020
Pen Testers Who Got Arrested Doing Their Jobs Tell All
Kelly Jackson Higgins, Executive Editor at Dark Reading,  8/5/2020
New 'Nanodegree' Program Provides Hands-On Cybersecurity Training
Nicole Ferraro, Contributing Writer,  8/3/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
Special Report: Computing's New Normal, a Dark Reading Perspective
This special report examines how IT security organizations have adapted to the "new normal" of computing and what the long-term effects will be. Read it and get a unique set of perspectives on issues ranging from new threats & vulnerabilities as a result of remote working to how enterprise security strategy will be affected long term.
Flash Poll
The Changing Face of Threat Intelligence
The Changing Face of Threat Intelligence
This special report takes a look at how enterprises are using threat intelligence, as well as emerging best practices for integrating threat intel into security operations and incident response. Download it today!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-15820
PUBLISHED: 2020-08-08
In JetBrains YouTrack before 2020.2.6881, the markdown parser could disclose hidden file existence.
CVE-2020-15821
PUBLISHED: 2020-08-08
In JetBrains YouTrack before 2020.2.6881, a user without permission is able to create an article draft.
CVE-2020-15823
PUBLISHED: 2020-08-08
JetBrains YouTrack before 2020.2.8873 is vulnerable to SSRF in the Workflow component.
CVE-2020-15824
PUBLISHED: 2020-08-08
In JetBrains Kotlin before 1.4.0, there is a script-cache privilege escalation vulnerability due to kotlin-main-kts cached scripts in the system temp directory, which is shared by all users by default.
CVE-2020-15825
PUBLISHED: 2020-08-08
In JetBrains TeamCity before 2020.1, users with the Modify Group permission can elevate other users' privileges.