VBS_AGENT.GQG

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It deletes registry entries, causing some applications and programs to not function properly.

It executes commands from a remote malicious user, effectively compromising the affected system.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It steals certain information from the system and/or the user.

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan creates the following folders:

• %Application Data%\Dropebox{username}{number}

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other System Modifications

This Trojan deletes the following files:

• %User StartUp%\AdobeUpdateManagementTool.lnk
• %User Temp%\swf.ico"

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It deletes the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
AdobeUpdateManagementTool = ""

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
c_last = ""

Backdoor Routine

This Trojan executes the following commands from a remote malicious user:

• info - Get System Information
• proc - Get running processes
• scrin - Take screenshot
• exe - Download and execute binary
• vbs - Download and execute VB Script
• ps1 - Download and execute powershell command
• dll - Not used
• delete - Uninstall self
• scrrunr - Not used

It connects to the following URL(s) to send and receive commands from a remote malicious user:

• http://{BLOCKED}al.strideindustrialusa.com

Download Routine

This Trojan saves the files it downloads using the following names:

• %Application Data%\Dropebox{username}{number}\screenshot__.ps1 - take screenshot
• %Application Data%\Dropebox{username}{number}\screenshot__.png - screenshot
• %Application Data%\Dropebox{username}{number}\exe__.exe - downloaded binary
• %Application Data%\Dropebox{username}{number}\vb__.vbs - downloaded VB script
• %Application Data%\Dropebox{username}{number}\ps1__.ps1 - downloaded powershell

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Information Theft

This Trojan steals the following information:

• OS Information:
  • OS Name
  • Version
  • Service Pack
  • OS Manufacturer
  • Windows Directory
  • Locale
  • Available Physical Memory
  • Total Virtual Memory
  • Available Virtual Memory
• System Information:
  • System Name
  • System Manufacturer
  • System Model
  • Time Zone
  • Total Physical Memory
  • Processor System Type
  • Processor
  • BIOS Version
• Networking information:
  • Computer name
  • Domain
  • User name
  • IP Address
  • Mac Address
• Screenshot
• List of Processes