Silent – Silence Trojan

Silent, also known as Silence, trojan is used to monitor a user’s machine so that over time it can obtain information on the software and activities being used within the system. At the time of publication, this malware has been targeting banks. It is capable of screen recording, data uploading and communicating with a Command and Control (C2) server.

Infection is achieved via phishing emails containing a malicious attachment which, when opened, infects the user’s computer via a JavaScript directing the user to an external URL. From here a .VBS script is executed and a final dropper (a win32 executable binary file) is downloaded and executed. It then downloads and executes malicious payloads. Once the final payload is installed, the attacker can observe services running on the infected computer.

Indicators of Compromise
File Hash (SHA256)

f5d76324cb8fcae7f00b6825e4c110ddfd6b32db452f1eca0f4cff958316869c (Player.dmg)

Kaspersky lab products detects the Silence trojan with the following verdicts:

Backdoor.Win32.Agent.dpke
Backdoor.Win32.Agent.dpiz
Trojan.Win32.Agentb.bwnk
Trojan.Win32.Agentb.bwni
Trojan-Downloader.JS.Agent.ocr
HEUR:Trojan.Win32.Generic

Resolution:

To prevent and detect a Trojan 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, 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