VBS_AGENT.GQG

 Analysis by: Cris Nowell Pantanilla

 ALIASES:

Worm.VBS.Agent.gq (Kaspersky), VBS/TrojanDownloader.Agent.OEP (ESET-NOD32)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Spammed via email

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.

  TECHNICAL DETAILS

File Size:

39,454 bytes

File Type:

VBS

Memory Resident:

Yes

Initial Samples Received Date:

23 Oct 2016

Payload:

Downloads files, Executes files, Connects to URLs/IPs

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

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.854.07

FIRST VSAPI PATTERN DATE:

23 Oct 2016

VSAPI OPR PATTERN File:

12.855.00

VSAPI OPR PATTERN Date:

24 Oct 2016

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  %Application Data%\Dropebox{username}{number}

Step 4

Restart in normal mode and scan your computer with your Trend Micro product for files detected as VBS_AGENT.GQG. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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