VBS_CINERA.DO

February 13, 2017
 Analysis by: Byron Jon Gelera
 ALIASES:

VBS/Zapchast.N!tr (Fortinet); Worm.VBS.Agent.bv (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 on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

4,213 bytes

File Type:

VBS

Memory Resident:

Yes

Initial Samples Received Date:

01 Feb 2017

Arrival Details

This worm 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 copies of itself in the Windows system folder and appends garbage code to the dropped copy to avoid easy detection. The dropped copies uses the following file names:

  • %System%\Win32.vbs

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
FIXEDFON.FON = "%System%\Win32.vbs"

Other System Modifications

This worm modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Vbsfile\DefaultIcon
(Default) = "%Windows%\Installer\90120000-0030-0000-0000-0000000FF1CE\wordicon.exe,1"

(Note: The default value data of the said registry entry is "%System%\WScript.exe,2".)

Propagation

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

  • {Removable Drive Letter}:\The_Cars.vbs

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.206.04

FIRST VSAPI PATTERN DATE:

07 Feb 2017

VSAPI OPR PATTERN File:

13.207.00

VSAPI OPR PATTERN Date:

08 Feb 2017

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

Restart in Safe Mode

[ Learn More ]

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • FIXEDFON.FON = "%System%\Win32.vbs"

Step 5

Restore this modified 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_LOCAL_MACHINE\SOFTWARE\Classes\ Vbsfile\DefaultIcon
    • From: (Default) = "%Windows%\Installer\90120000-0030-0000-0000-0000000FF1CE\wordicon.exe,1"
      To: (Default) = "%System%\WScript.exe,2"

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as VBS_CINERA.DO. 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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