Threat Intelligence

New Ransomware Attacks Endpoint Defenses

AVCrypt tries to disable anti-malware software before it can be detected and removed.

A newly discovered ransomware variant attempts to remove any anti-malware protection in place on a victim's computer before it begins its nefarious work.

A group of researchers that includes Lawrence Abrams (of bleepingcomputer.com), MalwareHunterTeam, and Michael Gillespie discovered the malware and reported it in a post on BleepingComputer. The malware, which the group of analysts and researchers is calling AVCrypt, first tries to identify and remove a number of Windows services that are required for two specific anti-virus packages, Windows Defender and Malwarebytes, to operate successfully.

Abrams said in his post that AVCrypt seems at best incomplete because of major missing pieces. While it does contact a command and control server and encrypt files, it doesn't actually include any ransom instructions or provisions for decryption.

In a Twitter conversation about the ransomware, several participants point out that other types of malware have been able to disable particular antivirus packages, but that this is new behavior for ransomware. It's also noted that AVCrypt specifically targets Malwarebytes and Windows Defender. Defender is the default antivirus package from Microsoft that's typically activated if the user decides not to install other AV software.

MalwareHunterTeam also pointed out in the Twitter exchange that AVCrypt will abort a shutdown sequence command in an attempt to prevent the user from staying safe by "pulling the plug" on a machine. The combination of behaviors could make a number of the standard processes for an emergency recovery unworkable.

While the specific ransomware variant discussed in the article is new, there are significant similarities to other malware code seen previously. In a Twitter discussion with Michael Gillespie, Microsoft's Windows Defender Security Intelligence tweeted, "#WindowsDefenderAV blocked this #ransomware at the onset using proactive cloud-based protection. We're seeing very limited instances of this ransomware, it does look like it's in development. We detect this new threat as Ransom:Win32/Pactelung.A."

It seems that the curtain has been pulled back on a very new, very immature ransomware variant before it could be released into the wild in its finished form. The delivery mechanisms for AVCrypt appear to be the standard methods seen in other ransomware, including malicious spam, drive-by URLs, and pirated software. For now, it appears that stringent applications of existing protection should protect organizations against AVCrypt.

Related Content:

Interop ITX 2018

Join Dark Reading LIVE for two cybersecurity summits at Interop ITX. Learn from the industry’s most knowledgeable IT security experts. Check out the security track here. Register with Promo Code DR200 and save $200.

Curtis Franklin Jr. is Senior Editor at Dark Reading. In this role he focuses on product and technology coverage for the publication. In addition he works on audio and video programming for Dark Reading and contributes to activities at Interop ITX, Black Hat, INsecurity, and ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Devastating Cyberattack on Email Provider Destroys 18 Years of Data
Jai Vijayan, Freelance writer,  2/12/2019
Up to 100,000 Reported Affected in Landmark White Data Breach
Kelly Sheridan, Staff Editor, Dark Reading,  2/12/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
5 Emerging Cyber Threats to Watch for in 2019
Online attackers are constantly developing new, innovative ways to break into the enterprise. This Dark Reading Tech Digest gives an in-depth look at five emerging attack trends and exploits your security team should look out for, along with helpful recommendations on how you can prevent your organization from falling victim.
Flash Poll
How Enterprises Are Attacking the Cybersecurity Problem
How Enterprises Are Attacking the Cybersecurity Problem
Data breach fears and the need to comply with regulations such as GDPR are two major drivers increased spending on security products and technologies. But other factors are contributing to the trend as well. Find out more about how enterprises are attacking the cybersecurity problem by reading our report today.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-7399
PUBLISHED: 2019-02-17
Amazon Fire OS before 5.3.6.4 allows a man-in-the-middle attack against HTTP requests for "Terms of Use" and Privacy pages.
CVE-2019-8392
PUBLISHED: 2019-02-17
An issue was discovered on D-Link DIR-823G devices with firmware 1.02B03. There is incorrect access control allowing remote attackers to enable Guest Wi-Fi via the SetWLanRadioSettings HNAP API to the web service provided by /bin/goahead.
CVE-2019-8394
PUBLISHED: 2019-02-17
Zoho ManageEngine ServiceDesk Plus (SDP) before 10.0 build 10012 allows remote attackers to upload arbitrary files via login page customization.
CVE-2019-8395
PUBLISHED: 2019-02-17
An Insecure Direct Object Reference (IDOR) vulnerability exists in Zoho ManageEngine ServiceDesk Plus (SDP) before 10.0 build 10007 via an attachment to a request.
CVE-2019-8389
PUBLISHED: 2019-02-17
A file-read vulnerability was identified in the Wi-Fi transfer feature of Musicloud 1.6. By default, the application runs a transfer service on port 8080, accessible by everyone on the same Wi-Fi network. An attacker can send the POST parameters downfiles and cur-folder (with a crafted ../ payload) ...