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TROJ_DLOADR.PSG

October 12, 2012
 ALIASES:

PWS:Win32/Zbot (Microsoft); Trojan.ADH.2 (Symantec); Trojan.Win32.Generic!BT (Sunbelt); Gen:Variant.Kazy.31832 (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild:

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies files, disabling programs and applications from properly running.

  TECHNICAL DETAILS

File Size:

221,696 bytes

File Type:

EXE

Initial Samples Received Date:

01 Oct 2011

Arrival Details

This Trojan 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 Trojan creates the following folders:

  • %Application Data%\Microsoft
  • %Application Data%\Microsoft\Windows Media
  • %Application Data%\Microsoft\Windows Media\9.0

(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.)

Other System Modifications

This Trojan modifies the following files:

  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.DTD

(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 deletes the following files:

  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML.bak
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNSD.XML
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNSR.XML
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML.done

(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 registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Health\{F3F092B7-52F3-4A2B-8601-C70D75129497}

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Preferences\ProxySettings

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Preferences\ProxySettings\
MMS

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Preferences\ProxySettings\
HTTP

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Preferences\ProxySettings\
RTSP

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows Media\WMSDK\General
UniqueID = "{E4217050-ADA1-469C-9507-4C32A84641A3}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows Media\WMSDK\General
ComputerName = "BRIAN-C0D045D8D"

HKEY_CURRENT_USER\Software\Microsoft\
Windows Media\WMSDK\General
VolumeSerialNumber = fbdff95

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Preferences\ProxySettings\
MMS
ProxyPort = 6db

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Preferences\ProxySettings\
HTTP
ProxyStyle = 1

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Preferences\ProxySettings\
HTTP
ProxyPort = 5

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Preferences\ProxySettings\
RTSP
ProxyPort = 22a

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Player\Tasks\
NowPlaying
InitFlags = 1

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows Media\WMSDK\Namespace
LocalBase = "%Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML"

(Note: The default value data of the said registry entry is %System Root%\Documents and Settings\Default User\Local Settings\Application Data\Microsoft\Windows Media\9.0\WMSDKNS.XML.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows Media\WMSDK\Namespace
DTDFile = "%Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.DTD"

(Note: The default value data of the said registry entry is %System Root%\Documents and Settings\Default User\Local Settings\Application Data\Microsoft\Windows Media\9.0\WMSDKNS.DTD.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows Media\WMSDK\Namespace
LocalDelta = "%Application Data%\Microsoft\Windows Media\9.0\WMSDKNSD.XML"

(Note: The default value data of the said registry entry is %System Root%\Documents and Settings\Default User\Local Settings\Application Data\Microsoft\Windows Media\9.0\WMSDKNSD.XML.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows Media\WMSDK\Namespace
RemoteDelta = "%Application Data%\Microsoft\Windows Media\9.0\WMSDKNSR.XML"

(Note: The default value data of the said registry entry is %System Root%\Documents and Settings\Default User\Local Settings\Application Data\Microsoft\Windows Media\9.0\WMSDKNSR.XML.)

It deletes the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
MediaPlayer\Health\{F3F092B7-52F3-4A2B-8601-C70D75129497}

Dropping Routine

This Trojan drops the following files:

  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML.bak
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML.done
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNSD.XML
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML

(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.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

Delete this registry key

[ 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\MediaPlayer\Health
    • {F3F092B7-52F3-4A2B-8601-C70D75129497}
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences
    • ProxySettings
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences\ProxySettings
    • MMS
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences\ProxySettings
    • HTTP
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences\ProxySettings
    • RTSP

Step 3

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 Media\WMSDK\General
    • UniqueID="{E4217050-ADA1-469C-9507-4C32A84641A3}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows Media\WMSDK\General
    • ComputerName="BRIAN-C0D045D8D"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows Media\WMSDK\General
    • VolumeSerialNumber=fbdff95
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences\ProxySettings\MMS
    • ProxyPort=6db
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences\ProxySettings\HTTP
    • ProxyStyle=1
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences\ProxySettings\HTTP
    • ProxyPort=5
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences\ProxySettings\RTSP
    • ProxyPort=22a
  • In HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Player\Tasks\NowPlaying
    • InitFlags=1

Step 4

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_CURRENT_USER\Software\Microsoft\Windows Media\WMSDK\Namespace
    • From: LocalBase="%Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML"
      To: LocalBase=%System Root%\Documents and Settings\Default User\Local Settings\Application Data\Microsoft\Windows Media\9.0\WMSDKNS.XML
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows Media\WMSDK\Namespace
    • From: DTDFile="%Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.DTD"
      To: DTDFile=%System Root%\Documents and Settings\Default User\Local Settings\Application Data\Microsoft\Windows Media\9.0\WMSDKNS.DTD
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows Media\WMSDK\Namespace
    • From: LocalDelta="%Application Data%\Microsoft\Windows Media\9.0\WMSDKNSD.XML"
      To: LocalDelta=%System Root%\Documents and Settings\Default User\Local Settings\Application Data\Microsoft\Windows Media\9.0\WMSDKNSD.XML
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows Media\WMSDK\Namespace
    • From: RemoteDelta="%Application Data%\Microsoft\Windows Media\9.0\WMSDKNSR.XML"
      To: RemoteDelta=%System Root%\Documents and Settings\Default User\Local Settings\Application Data\Microsoft\Windows Media\9.0\WMSDKNSR.XML

Step 5

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.
  • %Application Data%\Microsoft
  • %Application Data%\Microsoft\Windows Media
  • %Application Data%\Microsoft\Windows Media\9.0

Step 6

Search and delete these files

[ 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%\Microsoft\Windows Media\9.0\WMSDKNS.XML.bak
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML.done
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNSD.XML
  • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML

Step 7

Restore deleted/modified files and/or registry entries from backup

*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

    • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.XML
    • %Application Data%\Microsoft\Windows Media\9.0\WMSDKNS.DTD

Step 8

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