BKDR_WOODINI.A

 Analysis by: Erika Bianca Mendoza

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Upon execution, this backdoor terminates certain processes.

This backdoor may be dropped by other malware.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

81,408 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

08 Apr 2011

Payload:

Terminates processes

Arrival Details

This backdoor may be dropped by the following malware:

  • TROJ_ARTIEF.MR
  • TROJ_ARTIEF.EO
  • TROJ_EXLDROP.SM

Installation

This backdoor drops the following copies of itself into the affected system:

  • %Application Data%\ws2help.PNF
  • %Application Data%\IECheck.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It drops the following files:

  • %Application Data%\msvcr.dll
  • %system%\{random numbers}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • VistaDLLPro RUNNING

Autostart Technique

This backdoor drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

  • %Start Menu%\Programs\Startup\Internet Explorer Security Check.lnk

(Note: %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Profiles\{user name}\Start Menu on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu on Windows NT and C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003.)

Other Details

This backdoor deletes itself after execution.

NOTES:

It queries the value in the following registry to check installed applications:

SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall

If "DisplayName" matches any of the following strings, it does not continue with its routines:

  • Kaspersky
  • 360
  • Trend
  • COMODO
  • AVG
  • BitDefender
  • Avira Premium Security Suite
  • ESET
  • Avira
  • Norton Internet Security

It also terminates processes related to Kaspersky antivirus:

  • KSafeSvc.exe
  • KSafeTray.exe

  SOLUTION

Minimum Scan Engine:

8.900

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Remove malware files dropped/downloaded by BKDR_WOODINI.A

    TROJ_ARTIEF.MR
    TROJ_ARTIEF.EO
    TROJ_EXLDROP.SM

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete this file

[ Learn More ]
There may be some component 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%\msvcr.dll
%System%\{random numbers}
%Start Menu%\Programs\Startup\Internet Explorer Security Check.lnk

Step 5

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