VBS_KUBFACE.A


 ALIASES:

Worm:VBS/Jenxcus (Microsoft); Worm.VBS.Agent.gj (Kaspersky)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

371,156 bytes

File Type:

VBS

Memory Resident:

Yes

Initial Samples Received Date:

02 Oct 2017

Arrival Details

This Worm arrives via removable drives.

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 Worm drops the following copies of itself into the affected system:

  • %User Profile%\{Malware Filename}.wsf

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

This Worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Malware Name} = "wscript.exe //B "%User Profile%\{Malware Filename}.wsf""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{Malware Name} = "wscript.exe //B "%User Profile%\{Malware Filename}.wsf""

It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\{Malware Filename}.wsf ← copy of itself

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

Other System Modifications

This Worm adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\{Malware Filename}
{default} = false - {Date}

Propagation

This Worm drops the following copy(ies) of itself in all removable drives:

  • {Removable Drive Letter}:\{Malware Filename}.wsf

It creates shortcut files (.LNK) disguised as folders or files located on the affected drives pointing to the malware copy.

Other Details

This Worm connects to the following possibly malicious URL:

  • http://iamback.{BLOCKED}s.net:13/is-ready

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

12.136.01

FIRST VSAPI PATTERN DATE:

06 Nov 2015

VSAPI OPR PATTERN File:

12.137.00

VSAPI OPR PATTERN Date:

07 Nov 2015

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Identify and terminate files detected as VBS_KUBFACE.A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {Malware Name} = "wscript.exe //B "%User Profile%\{Malware Filename}.wsf""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {Malware Name} = "wscript.exe //B "%User Profile%\{Malware Filename}.wsf""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\{Malware Filename}
    • {default} = false - {Date}

Step 5

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • {Removable Drive Letter}:\{.LNK files pointing to malware}

Step 6

Scan your computer with your Trend Micro product to delete files detected as VBS_KUBFACE.A. 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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