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WORM_MALAS.A

May 25, 2013
 ALIASES:

ERROR (Microsoft); W32/Bindo.worm (McAfee); W32.Linkfars (Symantec); P2P-Worm.Win32.Malas.b (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Worm/Generic2.BUDS (AVG)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • 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.

It disables Task Manager, Registry Editor, and Folder Options.

  TECHNICAL DETAILS

File Size:

139,264 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

25 May 2013

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 the following copies of itself into the affected system:

  • %User Temp%\svchost.exe

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

It creates the following folders:

  • %Program Files%\Sound Utility
  • %Program Files%\XPCode

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

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
SoundMax = "%Program Files%\Sound Utility\Soundmax.exe"

Other System Modifications

This worm adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "2"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

(Note: The default value data of the said registry entry is 2.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = "2"

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

It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
Nofolderoptions = "1"

Dropping Routine

This worm drops the following files:

  • %Start Menu%\Programs\Accessories\Paint.lnk
  • %Start Menu%\Programs\Accessories\Calculator.lnk
  • %Common Startup%\Office Update.lnk
  • %System Root%\Autorun.inf
  • %Program Files%\XPCode\Games.lnk
  • %Program Files%\Common Files\Microsoft Shared\MSshare.exe
  • %Program Files%\Sound Utility\Soundmax.exe
  • %Windows%\Web\OfficeUpdate.exe
  • %Program Files%\Kazaa Lite\My Shared Folder\Sex_ScreenSaver.scr
  • %Program Files%\Kazaa Lite\My Shared Folder\Sex_Game.exe
  • %Program Files%\Kazaa\My Shared Folder\Sex_ScreenSaver.scr
  • %Program Files%\Kazaa\My Shared Folder\Sex_Game.exe
  • %Program Files%\Edonkey2000\Incoming\Sex_ScreenSaver.scr
  • %Program Files%\Edonkey2000\Incoming\Sex_Game.exe
  • %Program Files%\Icq\Shared Files\Sex_ScreenSaver.scr
  • %Program Files%\Icq\Shared Files\Sex_Game.exe
  • %Program Files%\emule\incoming\Sex_ScreenSaver.scr
  • %System Root%\autoply.exe
  • %Program Files%\emule\incoming\Sex_Game.exe
  • %Program Files%\Gnucleus\Downloads\Incoming\Sex_ScreenSaver.scr
  • %Program Files%\Gnucleus\Downloads\Incoming\Sex_Game.exe
  • %Program Files%\KMD\My Shared Folder\Sex_ScreenSaver.scr
  • %Program Files%\KMD\My Shared Folder\Sex_Game.exe
  • %Program Files%\Limewire\Shared\Sex_ScreenSaver.scr
  • %Program Files%\Limewire\Shared\Sex_Game.exe
  • %System Root%\Inetpub\ftproot\Sex_ScreenSaver.scr
  • %System Root%\Inetpub\ftproot\Sex_Game.exe
  • %Program Files%\XPCode\SexGame.exe
  • %Program Files%\XPCode\SexScreenSaver.scr
  • %Program Files%\XPCode\SexGameList.pif
  • \CWS07D210\C$\Documents and Settings\All Users\Start Menu\Programs\Startup\AdobeUpdate.exe

(Note: %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.. %Common Startup% is the system's shared Startup folder, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %Windows% is the Windows folder, which is usually C:\Windows.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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

Enable Registry Editor, Task Manager, and Folder options

[ Learn More ]
By doing this step, you also enable other applications/programs disabled by this malware/grayware/spyware.

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
    • SoundMax = "%Program Files%\Sound Utility\Soundmax.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ShowSuperHidden = "2"

Step 5

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: Hidden = "2"
      To: Hidden = ""2""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: HideFileExt = "2"
      To: HideFileExt = ""1""

Step 6

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %Start Menu%\Programs\Accessories\Paint.lnk
  • %Start Menu%\Programs\Accessories\Calculator.lnk
  • %Common Startup%\Office Update.lnk
  • %System Root%\Autorun.inf
  • %Program Files%\XPCode\Games.lnk
  • %Program Files%\Common Files\Microsoft Shared\MSshare.exe
  • %Program Files%\Sound Utility\Soundmax.exe
  • %Windows%\Web\OfficeUpdate.exe
  • %Program Files%\Kazaa Lite\My Shared Folder\Sex_ScreenSaver.scr
  • %Program Files%\Kazaa Lite\My Shared Folder\Sex_Game.exe
  • %Program Files%\Kazaa\My Shared Folder\Sex_ScreenSaver.scr
  • %Program Files%\Kazaa\My Shared Folder\Sex_Game.exe
  • %Program Files%\Edonkey2000\Incoming\Sex_ScreenSaver.scr
  • %Program Files%\Edonkey2000\Incoming\Sex_Game.exe
  • %Program Files%\Icq\Shared Files\Sex_ScreenSaver.scr
  • %Program Files%\Icq\Shared Files\Sex_Game.exe
  • %Program Files%\emule\incoming\Sex_ScreenSaver.scr
  • %System Root%\autoply.exe
  • %Program Files%\emule\incoming\Sex_Game.exe
  • %Program Files%\Gnucleus\Downloads\Incoming\Sex_ScreenSaver.scr
  • %Program Files%\Gnucleus\Downloads\Incoming\Sex_Game.exe
  • %Program Files%\KMD\My Shared Folder\Sex_ScreenSaver.scr
  • %Program Files%\KMD\My Shared Folder\Sex_Game.exe
  • %Program Files%\Limewire\Shared\Sex_ScreenSaver.scr
  • %Program Files%\Limewire\Shared\Sex_Game.exe
  • %System Root%\Inetpub\ftproot\Sex_ScreenSaver.scr
  • %System Root%\Inetpub\ftproot\Sex_Game.exe
  • %Program Files%\XPCode\SexGame.exe
  • %Program Files%\XPCode\SexScreenSaver.scr
  • %Program Files%\XPCode\SexGameList.pif
  • \CWS07D210\C$\Documents and Settings\All Users\Start Menu\Programs\Startup\AdobeUpdate.exe

Step 7

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.
  • %Program Files%\Sound Utility
  • %Program Files%\XPCode

Step 8

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