Remcos or Remote Control and Surveillance, marketed as a legitimate software by a Germany-based firm Breaking Security for remotely managing Windows systems is now widely used in multiple malicious campaigns by threat actors. Remcos is a sophisticated remote access Trojan (RAT) that can be used to fully control and monitor any Windows computer from XP and onwards.

The current campaign utilizes social engineering technique wherein threat actors are leveraging what’s new and trending worldwide. The phishing email contains a PDF offering CoronaVirus safety measures but in reality this PDF includes executable for a REMCOS RAT dropper that runs together with a VBS file executing the malware. The malware also adds Startup registry key at “HKCU\Software\Microsoft\Windows\CurrentVersion\RunOnce” for it to become persistent while the device affected has been restarted.

This Backdoor gathers the following information and sends it to its servers:

• Computer Information (OS version, computer name, system type, product name, primary adapter)
• User information (user access, user profile, user name, user domain)
• Processor information (processor revision number, processor level, processor identifier, processor architecture)

Sample Spam – Coronavirus-themed spam:

Behaviors

• Bypasses anti-virus products
• Maintains persistence on the targeted machine
• Runs as legitimate process by injecting to Windows process
• Gains admin privileges and disables user account control (UAC)

Capabilities

• Information Theft
• Backdoor commands

Impact

• Compromise system security - with backdoor capabilities that can execute malicious commands
• Violation of user privacy - gathers user credentials, logs keystroke and steals user information

Infection Routine

File Reputation

Predictive Machine Learning

Web Reputation

Anti Spam