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.

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
 

Recommended Reading:

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
COVID-19: Latest Security News & Commentary
Dark Reading Staff 7/1/2020
Ripple20 Threatens Increasingly Connected Medical Devices
Kelly Sheridan, Staff Editor, Dark Reading,  6/30/2020
DDoS Attacks Jump 542% from Q4 2019 to Q1 2020
Dark Reading Staff 6/30/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
The Threat from the Internet--and What Your Organization Can Do About It
This report describes some of the latest attacks and threats emanating from the Internet, as well as advice and tips on how your organization can mitigate those threats before they affect your business. Download it today!
Flash Poll
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-15478
PUBLISHED: 2020-07-01
The Journal theme before 3.1.0 for OpenCart allows exposure of sensitive data via SQL errors.
CVE-2020-6261
PUBLISHED: 2020-07-01
SAP Solution Manager (Trace Analysis), version 7.20, allows an attacker to perform a log injection into the trace file, due to Incomplete XML Validation. The readability of the trace file is impaired.
CVE-2020-15471
PUBLISHED: 2020-07-01
In nDPI through 3.2, the packet parsing code is vulnerable to a heap-based buffer over-read in ndpi_parse_packet_line_info in lib/ndpi_main.c.
CVE-2020-15472
PUBLISHED: 2020-07-01
In nDPI through 3.2, the H.323 dissector is vulnerable to a heap-based buffer over-read in ndpi_search_h323 in lib/protocols/h323.c, as demonstrated by a payload packet length that is too short.
CVE-2020-15473
PUBLISHED: 2020-07-01
In nDPI through 3.2, the OpenVPN dissector is vulnerable to a heap-based buffer over-read in ndpi_search_openvpn in lib/protocols/openvpn.c.