WiryJMPer Dropper

WiryJMPer is a newly observed dropper trojan that uses a novel obfuscation method to disguise its operations on affected systems.

Threat ID:: CC-3216
Category:: Trojan
Threat Severity:: Medium
Threat Vector:: Download
Published:: 16 September 2019 12:00 AM

Report a cyber attack: call 0300 303 5222 or email [email protected]

Summary

WiryJMPer is a newly observed dropper trojan that uses a novel obfuscation method to disguise its operations on affected systems.

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

Microsoft Windows - All versions

Threat details

At the time of publication, WiryJMPer is distributed as a binary file disguised as the legitimate application ABBC Coin Wallet (specifically version 3.9.1). It is presently unclear how this application is delivered, although there are unconfirmed reports indicating it is downloaded from third-party hosting sites. This file contains a sizeable amount of content from the WinBin2Iso (version 3.16) file converter, and uses multiple JMP loop-handling instructions to prevent static analysis and security tools from detecting it's presence.

When executed, WiryJMPer will create a bespoke virtual machine (VM) in memory to decrypt and combine several separate code sections contained within its binary to produce the intended payloads. Once these are installed, the VM is used to initiate a connection to a command and control server. WiryJMPer will also attempt to install legitimate versions of both ABBC Coin Wallet and WinBin2Iso.

Remediation steps

Type	Step
	To prevent and detect an infection, ensure that: A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails. All operating systems, anti-virus and other security products are kept up-to-date. Regular anti-virus and security scans are performed on your organisation’s estate. All day-to-day computer activities such as email and internet are performed using non-administrative accounts. Strong password policies are in place. Network, proxy and firewall logs should be monitored for suspicious activity. User accounts accessed from affected devices should be reset on a clean computer. Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

Type

Step

To prevent and detect an infection, ensure that:

A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails.
All operating systems, anti-virus and other security products are kept up-to-date.
Regular anti-virus and security scans are performed on your organisation’s estate.
All day-to-day computer activities such as email and internet are performed using non-administrative accounts.
Strong password policies are in place.
Network, proxy and firewall logs should be monitored for suspicious activity.
User accounts accessed from affected devices should be reset on a clean computer.
Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

Last edited: 14 February 2020 2:54 pm