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

4/30/2021
04:20 PM
Connect Directly
Twitter
LinkedIn
RSS
E-Mail
50%
50%

New Threat Group Carrying Out Aggressive Ransomware Campaign

UNC2447 observed targeting now-patched vulnerability in SonicWall VPN.

Researchers at FireEye Mandiant have observed what they describe as an aggressive new threat group exploiting a recently patched zero-day flaw in SonicWall's virtual private network (VPN) technology to drop ransomware called Fivehands on enterprise networks.

The group, which Mandiant is tracking as UNC2447, has been attempting to extort victims both with the ransomware itself and by stealing data from them and threatening to leak it on hacker forums, like many other ransomware operators recently. The group's victims — mostly in the US and Europe — include organizations across multiple industries such as telecommunications, healthcare, construction and engineering, food and beverage, and education.

Related Content:

Ransomware? Let's Call It What It Really Is: Extortionware

Special Report: Assessing Cybersecurity Risk in Today's Enterprises

New From The Edge: Ghost Town Security: What Threats Lurk in Abandoned Offices?

Tyler McLellan, principal threat analyst for advanced practices at Mandiant says the company is unsure about how many SonicWall VPN devices remain unpatched against CVE-2021-20016, a critical SQL injection vulnerability in SonicWall's Secure Mobile Access SMA 100 series remote access products. SonicWall issued a patch for the flaw, which is the one that UNC2447 is targeting, in February 2021.

"While we don’t have numbers on unpatched devices, Mandiant is aware that UNC2447-related threat actors are still in possession of credentials stolen from over 100 VPN appliances," McLellan says. "These affected organizations will remain at risk of ransomware attack even if patched, unless they enable multifactor authentication or reset all passwords."

Mandiant first observed signs of UNC2447 activity in November 2020, when it discovered a PowerShell dropper called Warprism being used to install the Cobalt Strike Beacon on systems belonging to two of its customers. In January and February, Mandiant spotted the threat actor using SombRAT — a backdoor packaged as a Windows executable — to deploy Fivehands ransomware on multiple victim networks.

BlackBerry Cylance was the first to spot SombRAT last December. McClellan says that since then, Mandiant has observed only UNC2447 using it and only to deploy Fivehands. According to Mandiant, SombRAT is an especially sophisticated tool designed primarily to download and execute plugins from a command-and-control server. The backdoor supports dozens of commands and includes multiple anti-detection features and mechanisms for obfuscating itself.

Past reporting by BlackBerry suggests that SombRAT could be a sophisticated mercenary cyber-espionage tool. Its use during multiple ransomware intrusions is unusual and noteworthy, McClellan says.

The Fivehands ransomware tool itself is not especially different from others of its kind. It appears to be a rewrite of a previous ransomware tool called Deathransom. It shares some similarities with HelloKitty, another derivative of Deathransom. UNC2447 appears to have begun using Fivehands only since the start of this year. Before that, the threat actor appears to have been using HelloKitty, Mandiant said in its report.

Fivehands is optimized to be substantially faster than HelloKitty, McLellan notes. "[It has] added a feature to accept a command line option to limit encryption to just a certain folder," he says. "These improvements could allow a Fivehands ransom operator to more quickly target a victim's important data for maximum impact."

While Fivehands itself is not particularly noteworthy, the encrypted launcher that it uses is very unusual because it uses a command line password to decrypt and load the ransomware into memory, McClellan says. "Even if the actor left the launcher executable on disk, it would be nearly impossible to crack the password to allow the victim to identify the ransomware strain used against them."

Mandiant says it has observed UNC2447 using multiple legitimate and dual-use tools and utilities, including Adfind, Bloodhound, Mimikatz, PChunter, and RCLONE.

Jai Vijayan is a seasoned technology reporter with over 20 years of experience in IT trade journalism. He was most recently a Senior Editor at Computerworld, where he covered information security and data privacy issues for the publication. Over the course of his 20-year ... View Full Bio
 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Edge-DRsplash-10-edge-articles
I Smell a RAT! New Cybersecurity Threats for the Crypto Industry
David Trepp, Partner, IT Assurance with accounting and advisory firm BPM LLP,  7/9/2021
News
Attacks on Kaseya Servers Led to Ransomware in Less Than 2 Hours
Robert Lemos, Contributing Writer,  7/7/2021
Commentary
It's in the Game (but It Shouldn't Be)
Tal Memran, Cybersecurity Expert, CYE,  7/9/2021
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
How Enterprises are Attacking the Cybersecurity Problem
Concerns over supply chain vulnerabilities and attack visibility drove some significant changes in enterprise cybersecurity strategies over the past year. Dark Reading's 2021 Strategic Security Survey showed that many organizations are staying the course regarding the use of a mix of attack prevention and threat detection technologies and practices for dealing with cyber threats.
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-2019-3556
PUBLISHED: 2021-10-26
HHVM supports the use of an "admin" server which accepts administrative requests over HTTP. One of those request handlers, dump-pcre-cache, can be used to output cached regular expressions from the current execution context into a file. The handler takes a parameter which specifies where o...
CVE-2021-35499
PUBLISHED: 2021-10-26
The Web Reporting component of TIBCO Software Inc.'s TIBCO Nimbus contains easily exploitable Stored Cross Site Scripting (XSS) vulnerabilities that allow a low privileged attacker to social engineer a legitimate user with network access to execute scripts targeting the affected system or the victim...
CVE-2021-41182
PUBLISHED: 2021-10-26
jQuery-UI is the official jQuery user interface library. Prior to version 1.13.0, accepting the value of the `altField` option of the Datepicker widget from untrusted sources may execute untrusted code. The issue is fixed in jQuery UI 1.13.0. Any string value passed to the `altField` option is now t...
CVE-2021-41183
PUBLISHED: 2021-10-26
jQuery-UI is the official jQuery user interface library. Prior to version 1.13.0, accepting the value of various `*Text` options of the Datepicker widget from untrusted sources may execute untrusted code. The issue is fixed in jQuery UI 1.13.0. The values passed to various `*Text` options are now al...
CVE-2021-41184
PUBLISHED: 2021-10-26
jQuery-UI is the official jQuery user interface library. Prior to version 1.13.0, accepting the value of the `of` option of the `.position()` util from untrusted sources may execute untrusted code. The issue is fixed in jQuery UI 1.13.0. Any string value passed to the `of` option is now treated as a...