ALIASES:

Trojan:Win32/Startpage.MP (Microsoft); Generic StartPage!rm (McAfee); Adware.Favorit (Symantec); PAK:UPX, Trojan.Win32.StartPage.agac (Kaspersky); Trojan.Win32.StartPage.agac (v) (Sunbelt); Trojan.Downloader.JNOT (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: 56,320 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 04 Nov 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:

  • %Program Files%\Internet Explorer\MUI
  • %Program Files%\Thunder
  • %Program Files%\Thunder\ComDlls\1143

(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).)

Other System Modifications

This Trojan deletes the following files:

  • %System Root%\Documents and Settings\Administrator\Start Menu\Programs\Internet Explorer.msm4

(Note: %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_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main\Frist

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
iiifile\ScriptEngine

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
anifile\ScriptEngine

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
anifile\shell

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
anifile\shell\open

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
anifile\shell\open\
command

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
fonfile\ScriptEngine

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Toolbar\WebBrowser
ITBar7Layout = {random values}

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Toolbar\WebBrowser
ITBarLayout = {random values}

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
HTTP
EditFlags = 2

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

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
https
EditFlags = 2

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

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
ftp
EditFlags = 2

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

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
gopher
EditFlags = 2

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

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
InternetShortcut
EditFlags = 2

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

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{FBF23B40-E3F0-101B-8488-00AA003E56F8}\InProcServer32
ThreadingModel = "Apartment"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.htm
Content Type = "text/html"

(Note: The default value data of the said registry entry is text/html.)

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.html
Content Type = "text/html"

(Note: The default value data of the said registry entry is text/html.)

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
InternetShortcut\shell\open
CLSID = "{FBF23B40-E3F0-101B-8488-00AA003E56F8}"

(Note: The default value data of the said registry entry is {FBF23B40-E3F0-101B-8488-00AA003E56F8}.)

Dropping Routine

This Trojan drops the following files:

  • %User Profile%\mm.ico
  • %User Profile%\game.ico
  • %User Profile%\taobao.ico
  • %User Profile%\movie.ico
  • %System Root%\b.txt
  • %User Temp%\TMP4352$.TMP
  • %User Temp%\RGI1.tmp
  • %Program Files%\Thunder\Update.exe
  • %Windows%\Downloaded Program Files\taobao.ico
  • %Windows%\Downloaded Program Files\game.ico
  • %Windows%\Downloaded Program Files\movie.ico
  • %Windows%\Downloaded Program Files\mm.ico
  • %Windows%\Downloaded Program Files\Update.exe
  • %Desktop%\ÌÔ±¦Íø.iii
  • %Desktop%\ÔÚÏßСÓÎÏ·.ani
  • %Favorites%\×îм«Æ·ÂÌÉ«ºÃµÄµçÓ°¿âÃâ·Ñ.¸ßÇå¸ßËÙ£¡ÌìÌì¸üÐÂ!!.html
  • %Favorites%\Öйú¸£Àû²ÊƱ£¬ÌåÓý²ÊƱµÄͶעÖÐÐÄ.²ÊƱ´óÓ®¼Ò£¡.html
  • %Favorites%\×îÐÂÔÚÏßС˵Ãâ·ÑµÄÔĶÁ.·á¸»ÄÚÈÝËٶȿìµÄС˵վ!.html
  • %Favorites%\ÌÔ±¦Íø - ÌÔ£¡ÎÒϲ»¶.html
  • %Favorites%\45575.comÔÚÏßµÄСÓÎÏ·.×îºÃÍæ×îÐÂ×î¿ì¿á³¬¼¶Ð¡ÓÎÏ·!.html
  • %Favorites%\µ±µ±Íø¡ªÍøÉϹºÎïÖÐÐÄ.html
  • %Favorites%\׿ԽÑÇÂíÑ·ÍøÉϹºÎïͼÊ飬ÊÖ»ú£¬ÊýÂ룬¼Òµç£¬»¯×±Æ·£¬ÖÓ±í£¬Ê×ÊεÈÔÚÏßÏúÊÛ.html
  • %Favorites%\¿´¿´µçÊÓ¾çÔÚÏß´óÈ«,,,×îºÃÂÌÉ«×îиßËÙÃâ·ÑµçÊÓ¾çÍøÕ¾!.html
  • %Favorites%\¼õ·Ê£¡¿ìµ½ÈÃÄã"&"¼â½Ð£¡ºþÄÏÎÀÊÓÍƼö×óÐýÈâ¼î¼õ·Ê!.html
  • %Favorites%\°¬³ÈÍŹº - ¾«Æ·ÍŹºÃ¿Ò»Ìì|¹ºÎï|ÍŹº|´òÕÛ!.html
  • %Favorites%\ÃÀÅ®·áÐØ´óÃؾ÷-20ÌìÄÚѸËÙÔö´ó´ó´ó!.html
  • %Favorites%\°¬³ÈÅ®×°--×îÃÀÀöʱÉеÄÅ®×°Æ·ÅÆ.ÃÀÅ®ÂòÒ£¬Ãëɱ°¬³ÈÅ®×°!!.html
  • %Favorites%\Á´½Ó\ÍøÖ·µ¼º½.html
  • %Favorites%\Á´½Ó\¸£²ÊÌå²Ê.html
  • %Favorites%\Á´½Ó\¡ô ÌÔ ±¦ Íø ¡ô.html
  • %Favorites%\Á´½Ó\ºÃÍæСÓÎÏ·.html
  • %Favorites%\Á´½Ó\µ±µ±Íø.html
  • %Favorites%\Á´½Ó\׿ԽÍø.html
  • %Favorites%\Á´½Ó\¿´µçÊÓ¾ç.html
  • %Favorites%\Á´½Ó\С˵Íø.html
  • %Favorites%\Á´½Ó\µ¥»úÓÎÏ·.html
  • %Favorites%\Á´½Ó\ÍøÂçµçÊÓ.html
  • %Favorites%\Á´½Ó\×î¿ìµçÓ°.html
  • %System Root%\Documents and Settings\Administrator\Start Menu\Programs\Internet Explorer.fon
  • %User Profile%\×ÀÃæ\Internet Explorer.fon

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.200

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

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\Internet Explorer\Main
    • Frist
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\iiifile
    • ScriptEngine
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\anifile
    • ScriptEngine
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\anifile
    • shell
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\anifile\shell
    • open
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\anifile\shell\open
    • command
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\fonfile
    • ScriptEngine

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\Internet Explorer\Toolbar\WebBrowser
    • ITBar7Layout={random values}
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Toolbar\WebBrowser
    • ITBarLayout={random values}

Step 4

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_LOCAL_MACHINE\SOFTWARE\Classes\HTTP
    • From: EditFlags=2
      To: EditFlags=2
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\https
    • From: EditFlags=2
      To: EditFlags=2
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ftp
    • From: EditFlags=2
      To: EditFlags=2
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\gopher
    • From: EditFlags=2
      To: EditFlags=2
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\InternetShortcut
    • From: EditFlags=2
      To: EditFlags=2
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{FBF23B40-E3F0-101B-8488-00AA003E56F8}\InProcServer32
    • From: ThreadingModel="Apartment"
      To: ThreadingModel=Apartment
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.htm
    • From: Content Type="text/html"
      To: Content Type=text/html
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.html
    • From: Content Type="text/html"
      To: Content Type=text/html
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\InternetShortcut\shell\open
    • From: CLSID="{FBF23B40-E3F0-101B-8488-00AA003E56F8}"
      To: CLSID={FBF23B40-E3F0-101B-8488-00AA003E56F8}

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.
  • %Program Files%\Internet Explorer\MUI
  • %Program Files%\Thunder
  • %Program Files%\Thunder\ComDlls\1143

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.
  • %User Profile%\mm.ico
  • %User Profile%\game.ico
  • %User Profile%\taobao.ico
  • %User Profile%\movie.ico
  • %System Root%\b.txt
  • %User Temp%\TMP4352$.TMP
  • %User Temp%\RGI1.tmp
  • %Program Files%\Thunder\Update.exe
  • %Windows%\Downloaded Program Files\taobao.ico
  • %Windows%\Downloaded Program Files\game.ico
  • %Windows%\Downloaded Program Files\movie.ico
  • %Windows%\Downloaded Program Files\mm.ico
  • %Windows%\Downloaded Program Files\Update.exe
  • %Desktop%\ÌÔ±¦Íø.iii
  • %Desktop%\ÔÚÏßСÓÎÏ·.ani
  • %Favorites%\×îм«Æ·ÂÌÉ«ºÃµÄµçÓ°¿âÃâ·Ñ.¸ßÇå¸ßËÙ£¡ÌìÌì¸üÐÂ!!.html
  • %Favorites%\Öйú¸£Àû²ÊƱ£¬ÌåÓý²ÊƱµÄͶעÖÐÐÄ.²ÊƱ´óÓ®¼Ò£¡.html
  • %Favorites%\×îÐÂÔÚÏßС˵Ãâ·ÑµÄÔĶÁ.·á¸»ÄÚÈÝËٶȿìµÄС˵վ!.html
  • %Favorites%\ÌÔ±¦Íø - ÌÔ£¡ÎÒϲ»¶.html
  • %Favorites%\45575.comÔÚÏßµÄСÓÎÏ·.×îºÃÍæ×îÐÂ×î¿ì¿á³¬¼¶Ð¡ÓÎÏ·!.html
  • %Favorites%\µ±µ±Íø¡ªÍøÉϹºÎïÖÐÐÄ.html
  • %Favorites%\׿ԽÑÇÂíÑ·ÍøÉϹºÎïͼÊ飬ÊÖ»ú£¬ÊýÂ룬¼Òµç£¬»¯×±Æ·£¬ÖÓ±í£¬Ê×ÊεÈÔÚÏßÏúÊÛ.html
  • %Favorites%\¿´¿´µçÊÓ¾çÔÚÏß´óÈ«,,,×îºÃÂÌÉ«×îиßËÙÃâ·ÑµçÊÓ¾çÍøÕ¾!.html
  • %Favorites%\¼õ·Ê£¡¿ìµ½ÈÃÄã"&"¼â½Ð£¡ºþÄÏÎÀÊÓÍƼö×óÐýÈâ¼î¼õ·Ê!.html
  • %Favorites%\°¬³ÈÍŹº - ¾«Æ·ÍŹºÃ¿Ò»Ìì|¹ºÎï|ÍŹº|´òÕÛ!.html
  • %Favorites%\ÃÀÅ®·áÐØ´óÃؾ÷-20ÌìÄÚѸËÙÔö´ó´ó´ó!.html
  • %Favorites%\°¬³ÈÅ®×°--×îÃÀÀöʱÉеÄÅ®×°Æ·ÅÆ.ÃÀÅ®ÂòÒ£¬Ãëɱ°¬³ÈÅ®×°!!.html
  • %Favorites%\Á´½Ó\ÍøÖ·µ¼º½.html
  • %Favorites%\Á´½Ó\¸£²ÊÌå²Ê.html
  • %Favorites%\Á´½Ó\¡ô ÌÔ ±¦ Íø ¡ô.html
  • %Favorites%\Á´½Ó\ºÃÍæСÓÎÏ·.html
  • %Favorites%\Á´½Ó\µ±µ±Íø.html
  • %Favorites%\Á´½Ó\׿ԽÍø.html
  • %Favorites%\Á´½Ó\¿´µçÊÓ¾ç.html
  • %Favorites%\Á´½Ó\С˵Íø.html
  • %Favorites%\Á´½Ó\µ¥»úÓÎÏ·.html
  • %Favorites%\Á´½Ó\ÍøÂçµçÊÓ.html
  • %Favorites%\Á´½Ó\×î¿ìµçÓ°.html
  • %System Root%\Documents and Settings\Administrator\Start Menu\Programs\Internet Explorer.fon
  • %User Profile%\×ÀÃæ\Internet Explorer.fon

Step 7

Scan your computer with your Trend Micro product to delete files detected as TROJ_STRTPG.SMX. 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 8

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. %System Root%\Documents and Settings\Administrator\Start Menu\Programs\Internet Explorer.msm4


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