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.

ABTV

12/17/2019
10:00 AM
Larry Loeb
Larry Loeb
Larry Loeb
50%
50%

TrickBot Drops an Anchor

New threat has been used in campaigns against financial, manufacturing, and retail businesses across the US and Europe.

Boston-based security firm Cybereason's Nocturnus Research Group has found a threatthat comes from a new malware that it calls Anchor. Anchor has been used in campaigns against financial, manufacturing and retail businesses across the US and Europe. These new attacks focus on stealing information from POS systems and other sensitive resources in the victims' network by compromising critical assets.

Cybereason says that the dropping anchor campaign started with a TrickBot infection and progressed into an operation targeting sensitive financial systems. The threat actors seems to selectively use a new variant of the rare Anchor_DNS tool. Anchor_DNS is a backdoor that uses the DNS protocol to stealthily communicate with C2 servers. In addition to the new Anchor_DNS variant, the attackers use a completely new and previously undocumented malware dubbed Anchor.

Cybereason notes that the Anchor malware is "a backdoor used very selectively on high-profile targets, and appears to be tightly connected to TrickBot, potentially even authored by the same individuals who created TrickBot."

It found that some of the tools and techniques detailed in its report resemble past attacks that were linked to the financially motivated FIN6 threat actor, a group that is known to target POS systems and has been linked to TrickBot infections in the past.

The attack starts with a phishing email that contains a malicious link to a file hosted on Google Docs named "Annual Bonus Report.doc". This differs from the usual email attachment. After TrickBot establishes Internet access and sends information about the location of the target machine, it starts its malicious activity.

The attacker also uses PowerShell to test DNS entry settings. They use the command -q=srv_kerberos_tcp on the process nslookup.exe to open an interactive shell. They use the shell to expand their search to other machines on the network by searching for things like a list of the domain controllers.

If they find they are on a high-value target, they escalate their efforts by switching to interactive hacking: reconnaissance, credential dumping, lateral movement and in some cases the mass deployment of ransomware across endpoints that are connected to the domain controller.

Anchor and Anchor_DNS are both directly linked to TrickBot infections, since they are downloaded by TrickBot as secondary payloads after the primary one has been installed.

The Anchor payload is delivered by AnchorInstaller which unpacks the Anchor DLL and drops it in the %SYSTEMROOT% or %SYSTEMROOT%\System32 folder. The dropped DLL is loaded by the service netTcpSvc, which is created by the malware.

The malware's binary is signed, which is meant to provide a level of credibility and integrity to a binary from the developer, and to guarantee that the binary has not been tampered with. It can also bypass some security solutions that grant trust to signed binaries.

Anchor as well as older versions of Anchor_DNS implement the exact same self deletion routine using two sets of commands to ensure that the dropper is deleted once the malware was successfully deployed.

Anchor is part of the evolution of TrickBot into a multi-phasic threat that can not only do ransomware, but steal information as part of its operation.

— Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other things, a consulting editor for BYTE magazine and senior editor for the launch of WebWeek.

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Cloud Security Threats for 2021
Or Azarzar, CTO & Co-Founder of Lightspin,  12/3/2020
Why Vulnerable Code Is Shipped Knowingly
Chris Eng, Chief Research Officer, Veracode,  11/30/2020
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Write a Caption, Win an Amazon Gift Card! Click Here
Latest Comment: This comment is waiting for review by our moderators.
Current Issue
2021 Top Enterprise IT Trends
We've identified the key trends that are poised to impact the IT landscape in 2021. Find out why they're important and how they will affect you today!
Flash Poll
Assessing Cybersecurity Risk in Todays Enterprises
Assessing Cybersecurity Risk in Todays Enterprises
COVID-19 has created a new IT paradigm in the enterprise and a new level of cybersecurity risk. This report offers a look at how enterprises are assessing and managing cyber-risk under the new normal.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2020-27772
PUBLISHED: 2020-12-04
A flaw was found in ImageMagick in coders/bmp.c. An attacker who submits a crafted file that is processed by ImageMagick could trigger undefined behavior in the form of values outside the range of type `unsigned int`. This would most likely lead to an impact to application availability, but could po...
CVE-2020-27773
PUBLISHED: 2020-12-04
A flaw was found in ImageMagick in MagickCore/gem-private.h. An attacker who submits a crafted file that is processed by ImageMagick could trigger undefined behavior in the form of values outside the range of type `unsigned char` or division by zero. This would most likely lead to an impact to appli...
CVE-2020-28950
PUBLISHED: 2020-12-04
The installer of Kaspersky Anti-Ransomware Tool (KART) prior to KART 4.0 Patch C was vulnerable to a DLL hijacking attack that allowed an attacker to elevate privileges during installation process.
CVE-2020-27774
PUBLISHED: 2020-12-04
A flaw was found in ImageMagick in MagickCore/statistic.c. An attacker who submits a crafted file that is processed by ImageMagick could trigger undefined behavior in the form of a too large shift for 64-bit type `ssize_t`. This would most likely lead to an impact to application availability, but co...
CVE-2020-27775
PUBLISHED: 2020-12-04
A flaw was found in ImageMagick in MagickCore/quantum.h. An attacker who submits a crafted file that is processed by ImageMagick could trigger undefined behavior in the form of values outside the range of type unsigned char. This would most likely lead to an impact to application availability, but c...