Nemucod Downloader

Nemucod is a trojan used to deliver other malicious files and is believed to be linked to Eastern European cybercrime groups.

Threat ID:: CC-1417
Category:: Spyware, Trojan
Threat Severity:: Medium
Threat Vector:: Macro
Published:: 17 May 2017 12:00 AM

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Summary

Nemucod is a trojan used to deliver other malicious files and is believed to be linked to Eastern European cybercrime groups.

Threat details

Nemucod is delivered via phishing or spam emails containing malicious documents. When opened, these use Microsoft Office Macros to execute a password-protected Visual Basic for Applications (VBA) script to install Nemucod. It has also been observed in a small number of cases being distributed as a Delphi-compiled executable file.

Payloads are written in heavily obfuscated JScript code to avoid detection by signature-based analysis. Once this code is executed a connection to the command and control (C2) server is made and the malware is downloaded.

Remediation advice

To prevent and detect a trojan infection, ensure that:

Remediation steps

Type	Step
	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, antivirus and other security products are kept up to date. All day to day computer activities such as email and internet are performed using non-administrative accounts. Strong password policies are in place and password reuse is discouraged. Network, proxy and firewall logs should be monitored for suspicious activity. User accounts accessed from infected machines should be reset on a clean computer

Type

Step

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, antivirus and other security products are kept up to date.
All day to day computer activities such as email and internet are performed using non-administrative accounts.
Strong password policies are in place and password reuse is discouraged.
Network, proxy and firewall logs should be monitored for suspicious activity.
User accounts accessed from infected machines should be reset on a clean computer

Last edited: 14 January 2022 8:31 am