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TROJ_DELF.DFC

October 12, 2012
 ALIASES:

Trojan.ADH.2 (Symantec); PAK:PE_Patch.PECompact, PAK:PecBundle, PAK:PECompact (Kaspersky); Trojan.Win32.Generic!SB.0 (Sunbelt); Trojan.Generic.7055331 (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: Yes

  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.

  TECHNICAL DETAILS

File Size:

329,680 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

06 May 2012

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 drops the following copies of itself into the affected system:

  • %User Temp%\{malware file name}

(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.)

It creates the following folders:

  • %Program Files%\search On

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
search On = "%Program Files%\search On\searchon.exe"

It registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\explorer\
Browser Helper Objects\{49D28F17-5837-4A12-8E2B-C246CA55F44B}

Other System Modifications

This Trojan deletes the following files:

  • %User Temp%\{malware file name}
  • %System Root%\RESTAR~1.BAT

(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.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data

HKEY_CLASSES_ROOT\CLSID\{49D28F17-5837-4A12-8E2B-C246CA55F44B}

HKEY_CLASSES_ROOT\CLSID\{49D28F17-5837-4A12-8E2B-C246CA55F44B}\
InprocServer32

HKEY_CLASSES_ROOT\search_on.Search On

HKEY_CLASSES_ROOT\search_on.Search On\Clsid

HKEY_CLASSES_ROOT\CLSID\{49D28F17-5837-4A12-8E2B-C246CA55F44B}\
ProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
search On

HKEY_LOCAL_MACHINE\SOFTWARE\searchOnLoader

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
{49D28F17-5837-4A12-8E2B-C246CA55F44B}

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1F3EA144C4CA46 = "00CA"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
19465746DF347A = "F525CAF25051"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1CCE4785AC0D6C9297753585 = "1AF0C6F7217CDB46AD8FC6228D7E"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
04BBBEAE46E0F9286669 = "07FE9ED0"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
00ED0FABC1B922F8D1AD903E4A2D0EAE6D5D = "0D63DD793A080651352D4E442B4F6E58"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
00ED0FABC1B922F8D1AD903E = "2DF682C645981980640D80894BFB"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
0A20E4A92F12697F8E009CBFB7F07A0ED0683AD9 = "0A20E4A92F1201A3FFA1"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
0A20E4A92F12697F8E009CBFB7F0 = "2AB4077A42945359"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1B5C99B7F005320788D92C9822B2CBCFFAD9 = "0ED5B154AAC794F608"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1B5C99B7F005320788D92C98 = "2E581E78841CD3"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1819B117E8A22F400B2BE5FC4A9226B9305556B782F2E6 = "1819B117E8C0C54808"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1819B117E8A22F400B2BE5FC4A9226B930 = "388CF747C4E548"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
0172590419AD3E27EBA45705FF9E = "3A47A539F342F247510C300D9C"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1CCE4785AC0D79261A25947882 = "3A47A539F342C23A39DD3092"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1B4CCD033C93083A4184FEB1C09892 = "3A47A539F342C23A6517D87E41"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
08411FE997 = "F525CAF250513B53353B0893C5"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
19464AC8B4C9520C55597210 = "1AF0C6F7217CB4C3F8"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1AFCF8CCF70F4FE686029AE9 = "1AF0C6F7217CB4C3F8"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1AFCF8CCF70F4FF12352D459 = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
00C68C0AC891FEB4CB8CC5834641A9 = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1B4CC94BC5BDD7 = "1ADAA034E49F662698B845F6FE0EF33290A0"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
1CCDEB9371A561E444F4 = "07DE"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
0490 = "78271C"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On\
Data
194651D07B8ED8674663DE363E = "F525CAF25051"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On
153Config.oBs = "2010070102"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On
SearchOn.exe = "2011031801"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On
DownFileInfo.oBs = "2010011501"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On
Search_On.dll = "2011053101"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{49D28F17-5837-4A12-8E2B-C246CA55F44B}\InprocServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{49D28F17-5837-4A12-8E2B-C246CA55F44B}
NoExplorer = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On
Guide.oBs = "2011032908"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On
Query.oBs = "2011042901"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On
Version = "2011053101"

HKEY_LOCAL_MACHINE\SOFTWARE\searchOnLoader
Search On = "%Program Files%\Search On\searchon.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
search On
DisplayName = "¼­Ä¡¿Â"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
search On
UninstallString = "%Program Files%\Search On\searchon.exe REMOVE"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
search On
DisplayIcon = "%Program Files%\Search On\searchon.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Search On
Exec = "{random values}"

Dropping Routine

This Trojan drops the following files:

  • %System%\config.o
  • %User Temp%\downfileinfo.oN
  • %User Temp%\153Config.oBs
  • %User Temp%\SearchOn.exe
  • %User Temp%\DownFileInfo.oBs
  • %Program Files%\search On\DownFileInfo.o
  • %User Temp%\Search_On.dll
  • %User Temp%\Guide.oBs
  • %Program Files%\search On\guide.o
  • %User Temp%\Query.oBs
  • %Program Files%\search On\query.o
  • %Program Files%\Search On\version.txt
  • %System Root%\Restart20.bat

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %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.. %Program Files% is the default Program Files folder, usually C:\Program Files.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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

Restart in Safe Mode

[ Learn More ]

Step 3

Close all opened browser windows

Step 4

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_LOCAL_MACHINE\SOFTWARE\Search On
    • Data
  • In HKEY_CLASSES_ROOT\CLSID
    • {49D28F17-5837-4A12-8E2B-C246CA55F44B}
  • In HKEY_CLASSES_ROOT\CLSID\{49D28F17-5837-4A12-8E2B-C246CA55F44B}
    • InprocServer32
  • In HKEY_CLASSES_ROOT
    • search_on.Search On
  • In HKEY_CLASSES_ROOT\search_on.Search On
    • Clsid
  • In HKEY_CLASSES_ROOT\CLSID\{49D28F17-5837-4A12-8E2B-C246CA55F44B}
    • ProgID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
    • search On
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • searchOnLoader
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes
    • {49D28F17-5837-4A12-8E2B-C246CA55F44B}

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • search On = "%Program Files%\search On\searchon.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1F3EA144C4CA46 = "00CA"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 19465746DF347A = "F525CAF25051"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1CCE4785AC0D6C9297753585 = "1AF0C6F7217CDB46AD8FC6228D7E"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 04BBBEAE46E0F9286669 = "07FE9ED0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 00ED0FABC1B922F8D1AD903E4A2D0EAE6D5D = "0D63DD793A080651352D4E442B4F6E58"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 00ED0FABC1B922F8D1AD903E = "2DF682C645981980640D80894BFB"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 0A20E4A92F12697F8E009CBFB7F07A0ED0683AD9 = "0A20E4A92F1201A3FFA1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 0A20E4A92F12697F8E009CBFB7F0 = "2AB4077A42945359"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1B5C99B7F005320788D92C9822B2CBCFFAD9 = "0ED5B154AAC794F608"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1B5C99B7F005320788D92C98 = "2E581E78841CD3"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1819B117E8A22F400B2BE5FC4A9226B9305556B782F2E6 = "1819B117E8C0C54808"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1819B117E8A22F400B2BE5FC4A9226B930 = "388CF747C4E548"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 0172590419AD3E27EBA45705FF9E = "3A47A539F342F247510C300D9C"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1CCE4785AC0D79261A25947882 = "3A47A539F342C23A39DD3092"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1B4CCD033C93083A4184FEB1C09892 = "3A47A539F342C23A6517D87E41"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 08411FE997 = "F525CAF250513B53353B0893C5"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 19464AC8B4C9520C55597210 = "1AF0C6F7217CB4C3F8"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1AFCF8CCF70F4FE686029AE9 = "1AF0C6F7217CB4C3F8"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1AFCF8CCF70F4FF12352D459 = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 00C68C0AC891FEB4CB8CC5834641A9 = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1B4CC94BC5BDD7 = "1ADAA034E49F662698B845F6FE0EF33290A0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 1CCDEB9371A561E444F4 = "07DE"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 0490 = "78271C"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On\Data
    • 194651D07B8ED8674663DE363E = "F525CAF25051"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On
    • 153Config.oBs = "2010070102"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On
    • SearchOn.exe = "2011031801"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On
    • DownFileInfo.oBs = "2010011501"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On
    • Search_On.dll = "2011053101"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{49D28F17-5837-4A12-8E2B-C246CA55F44B}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{49D28F17-5837-4A12-8E2B-C246CA55F44B}
    • NoExplorer = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On
    • Guide.oBs = "2011032908"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On
    • Query.oBs = "2011042901"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On
    • Version = "2011053101"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\searchOnLoader
    • Search On = "%Program Files%\Search On\searchon.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\search On
    • DisplayName = "¼­Ä¡¿Â"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\search On
    • UninstallString = "%Program Files%\Search On\searchon.exe REMOVE"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\search On
    • DisplayIcon = "%Program Files%\Search On\searchon.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Search On
    • Exec = "{random values}"

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.
  • %System%\config.o
  • %User Temp%\downfileinfo.oN
  • %User Temp%\153Config.oBs
  • %User Temp%\SearchOn.exe
  • %User Temp%\DownFileInfo.oBs
  • %Program Files%\search On\DownFileInfo.o
  • %User Temp%\Search_On.dll
  • %User Temp%\Guide.oBs
  • %Program Files%\search On\guide.o
  • %User Temp%\Query.oBs
  • %Program Files%\search On\query.o
  • %Program Files%\Search On\version.txt
  • %System Root%\Restart20.bat

Step 7

Search and delete this folder

[ 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%\search On

Step 8

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

Step 9

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %User Temp%\{malware file name}
  • %System Root%\RESTAR~1.BAT


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