Analysis by: John Donnie Celestre

ALIASES:

Trojan-Downloader.VBS.Agent.madu (KASPERSKY); Trojan.Downloader.VBS.HV (BITDEFENDER)

 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: 187,866 bytes
File Type: VBS
Memory Resident: Yes
Initial Samples Received Date: 11 May 2018

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 adds the following folders:

  • %Application Data%\Adobe PhotoShop
  • %Application Data%\Adobe PhotoShop\Public
  • %Application Data%\Adobe PhotoShop\Public\XNXX
  • %Application Data%\Adobe PhotoShop\Public\MUSIC
  • %Application Data%\Adobe PhotoShop\Public\DCIM
  • %Application Data%\Adobe PhotoShop\Public\MOVIES
  • %Application Data%\Adobe PhotoShop\Public\VIDEO
  • %System Root%\Adobe
  • %Removable Drive%\Adobe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It drops the following files:

  • %Application Data%\Adobe PhotoShop\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Startrun.pif
  • %Application Data%\Adobe PhotoShop\runsc.exe
  • %Application Data%\Adobe PhotoShop\Public\XNXX\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\XNXX\Video.Mp4.lnk
  • %Application Data%\Adobe PhotoShop\Public\MUSIC\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\MUSIC\Music.Mp3.lnk
  • %Application Data%\Adobe PhotoShop\Public\DCIM\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\DCIM\Pictur.jpg.lnk
  • %Application Data%\Adobe PhotoShop\Public\MOVIES\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\MOVIES\Movies.Mp4.lnk
  • %Application Data%\Adobe PhotoShop\Public\VIDEO\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\VIDEO\YouTube.Flv.lnk
  • %System Root%\Adobe\Pictur.Png
  • %System Root%\Adobe\runsc.exe
  • %Removable Drive%\Adobe\Pictur.Png
  • %Removable Drive%\Adobe\runsc.exe
  • %Removable Drive%\DCIM.lnk

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, and 8.. %System Root% is the Windows root folder, where it usually is C:\ 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_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Adobe PhotoShop = "%Application Data%\Adobe PhotoShop\Startrun.pif" /E:Vbscript.Encode "%Application Data%\Adobe PhotoShop\Pictur.Png"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
Adobe PhotoShop = "%Application Data%\Adobe PhotoShop\Startrun.pif" /E:Vbscript.Encode "%Application Data%\Adobe PhotoShop\Pictur.Png"

Other System Modifications

This Worm adds the following registry entries:

HKEY_CURRENT_USER\Software
Adobe PhotoShop = {True or False} - {Date of Infection}

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
System
EnableLUA = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software
Adobe PhotoShop = {True or False} - {Date of Infection}

Other Details

This Worm connects to the following possibly malicious URL:

  • mr-wolf.{BLOCKED}ctme.net
  • mr-wolf.{BLOCKED}c.net

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.806.02
FIRST VSAPI PATTERN DATE: 11 Feb 2019
VSAPI OPR PATTERN File: 14.807.00
VSAPI OPR PATTERN Date: 12 Feb 2019

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Adobe PhotoShop = "%Application Data%\Adobe PhotoShop\Startrun.pif"  /E:Vbscript.Encode "%Application Data%\Adobe PhotoShop\Pictur.Png";
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • Adobe PhotoShop = "%Application Data%\Adobe PhotoShop\Startrun.pif"  /E:Vbscript.Encode "%Application Data%\Adobe PhotoShop\Pictur.Png";

Step 5

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
    • Adobe PhotoShop = {True or False} - {Date of Infection}

Step 6

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: ShowSuperHidden = 0
      To: ShowSuperHidden = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System
    • From: EnableLUA = 0
      To: EnableLUA = 1

Step 7

Search and delete these files

[ 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.
  • %Application Data%\Adobe PhotoShop\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Startrun.pif
  • %Application Data%\Adobe PhotoShop\runsc.exe
  • %Application Data%\Adobe PhotoShop\Public\XNXX\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\XNXX\Video.Mp4.lnk
  • %Application Data%\Adobe PhotoShop\Public\MUSIC\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\MUSIC\Music.Mp3.lnk
  • %Application Data%\Adobe PhotoShop\Public\DCIM\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\DCIM\Pictur.jpg.lnk
  • %Application Data%\Adobe PhotoShop\Public\MOVIES\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\MOVIES\Movies.Mp4.lnk
  • %Application Data%\Adobe PhotoShop\Public\VIDEO\Pictur.Png
  • %Application Data%\Adobe PhotoShop\Public\VIDEO\YouTube.Flv.lnk
  • %System Root%\Adobe\Pictur.Png
  • %System Root%\Adobe\runsc.exe
  • %Removable Drive%\Adobe\Pictur.Png
  • %Removable Drive%\Adobe\runsc.exe
  • %Removable Drive%\DCIM.lnk

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Worm.VBS.DUNIHI.YYSWJ. 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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