ALIASES:

Trojan:Win32/Startpage.OR (Microsoft); Generic StartPage!bbc (McAfee); Trojan.Gen (Symantec); Trojan.Win32.Pasta.oit (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Generic.6397348 (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.

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

  TECHNICAL DETAILS

File Size: 826,664 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 12 Dec 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.

Other System Modifications

This Trojan modifies the following files:

  • %System%\drivers\etc\hosts
  • %Start Menu%\Programs\Internet Explorer.lnk

(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.. %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.)

It deletes the following files:

  • %Desktop%\Internet Explorer.url
  • %Desktop%\ÌÔ±¦Íø.lnk
  • %Desktop%\Internet Explorer.html
  • %Desktop%\360°²È«ÎÀÊ¿.lnk
  • %Desktop%\360Èí¼þ¹Ü¼Ò.lnk
  • %Desktop%\360ɱ¶¾.lnk
  • %Desktop%\ÈðÐÇɱ¶¾Èí¼þ.lnk
  • %Desktop%\ÐÞ¸´ÈðÐÇÈí¼þ.lnk
  • %Desktop%\Õ˺ű£ÏÕ¹ñ.lnk
  • %Start Menu%\Internet Explorer.url
  • %Start Menu%\ÌÔ±¦Íø.lnk
  • %Start Menu%\Internet Explorer.html
  • %Start Menu%\Programs\Internet Explorer.url
  • %Start Menu%\Programs\ÌÔ±¦Íø.lnk
  • %Start Menu%\Programs\Internet Explorer.html
  • %User Profile%\Quick Launch\Internet Explorer.url
  • %User Profile%\Quick Launch\ÌÔ±¦Íø.lnk
  • %User Profile%\Quick Launch\Internet Explorer.html
  • %User Profile%\Quick Launch\Æô¶¯ Internet Explorer ä¯ÀÀÆ÷.lnk
  • %User Profile%\Quick Launch\ÈðÐÇɱ¶¾Èí¼þ.lnk
  • %User Profile%\360se\360se_s.ini
  • %User Profile%\×ÀÃæ\Internet Explorer.lnk
  • %User Profile%\×ÀÃæ\ÌÔ±¦É̳Ç.lnk
  • %System%\drivers\etc\hosts

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

It adds the following registry keys:

HKEY_CLASSES_ROOT\Pz

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\
DefaultIcon

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\
Shell\ÊôÐÔ(&R)\Command

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\
Shell\ɾ³ý(&D)\Command

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\
Shell\ÖØÃüÃû(&M)\Command

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\
Shell\Open(&O)\Command

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\
ShellFolder

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Desktop\NameSpace\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\
DefaultIcon

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\
Shell\ÊôÐÔ(&R)\Command

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\
Shell\ɾ³ý(&D)\Command

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\
Shell\ÖØÃüÃû(&M)\Command

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\
Shell\Open(&O)\Command

HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\
ShellFolder

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Desktop\NameSpace\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Pz
1 = 132df6b

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Pz
5 = 27497

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Pz
10 = 1

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel
HomePage = 1

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "http://{BLOCKED}l.cn/s"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome.)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Start Page = "http://{BLOCKED}l.cn/s"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home.)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\SuperHidden

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\HideFileExt

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\TypedUrls

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
NOHIDDEN

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden

Dropping Routine

This Trojan drops the following files:

  • %System%\msscp.reg
  • %Program Files%\Common Files\System\taobao.ico
  • D:\360\svchost.exe
  • %Windows%\web\Index.htm
  • %Start Menu%\ÌÔ±¦ÈÈÂô.lnk
  • %Windows%\web\Index.html
  • %Start Menu%\Internet Explorer.lnk
  • %Start Menu%\Programs\ÌÔ±¦ÈÈÂô.lnk
  • %User Profile%\Quick Launch\Internet Explorer.lnk
  • %Favorites%\ÉÏÍøµ¼º½.url

(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.. %Program Files% is the default Program Files folder, usually C:\Program Files.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %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.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %Favorites% is the current user's Favorites folder, which is usually C:\Windows\Favorites on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Favorites on Windows NT, and C:\Documents and Settings\{user name}\Favorites 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_CLASSES_ROOT
    • Pz
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer
    • Control Panel
  • In HKEY_CLASSES_ROOT\CLSID
    • {F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}
    • DefaultIcon
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\Shell\ÊôÐÔ(&R)
    • Command
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\Shell\ɾ³ý(&D)
    • Command
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\Shell\ÖØÃüÃû(&M)
    • Command
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}\Shell\Open(&O)
    • Command
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}
    • ShellFolder
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Desktop\NameSpace
    • {F3CA57DF-C5DA-11CF-8F28-00AA0060FD42}
  • In HKEY_CLASSES_ROOT\CLSID
    • {F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}
    • DefaultIcon
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\Shell\ÊôÐÔ(&R)
    • Command
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\Shell\ɾ³ý(&D)
    • Command
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\Shell\ÖØÃüÃû(&M)
    • Command
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}\Shell\Open(&O)
    • Command
  • In HKEY_CLASSES_ROOT\CLSID\{F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}
    • ShellFolder
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Desktop\NameSpace
    • {F3CA57DF-C5DA-11CF-8F28-00AA0060FD43}

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\CurrentVersion\Explorer\Advanced
    • ShowSuperHidden=1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Pz
    • 1=132df6b
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Pz
    • 5=27497
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Pz
    • 10=1
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Control Panel
    • HomePage=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\Internet Explorer\Main
    • From: Start Page="http://{BLOCKED}l.cn/s"
      To: Start Page=http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Start Page="http://{BLOCKED}l.cn/s"
      To: Start Page=http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home

Step 5

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%\msscp.reg
  • %Program Files%\Common Files\System\taobao.ico
  • D:\360\svchost.exe
  • %Windows%\web\Index.htm
  • %Start Menu%\ÌÔ±¦ÈÈÂô.lnk
  • %Windows%\web\Index.html
  • %Start Menu%\Internet Explorer.lnk
  • %Start Menu%\Programs\ÌÔ±¦ÈÈÂô.lnk
  • %User Profile%\Quick Launch\Internet Explorer.lnk
  • %Favorites%\ÉÏÍøµ¼º½.url

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT_003867.TOMB. 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 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.

    • %System%\drivers\etc\hosts
    • %Start Menu%\Programs\Internet Explorer.lnk

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.

  • %Desktop%\Internet Explorer.url
  • %Desktop%\ÌÔ±¦Íø.lnk
  • %Desktop%\Internet Explorer.html
  • %Desktop%\360°²È«ÎÀÊ¿.lnk
  • %Desktop%\360Èí¼þ¹Ü¼Ò.lnk
  • %Desktop%\360ɱ¶¾.lnk
  • %Desktop%\ÈðÐÇɱ¶¾Èí¼þ.lnk
  • %Desktop%\ÐÞ¸´ÈðÐÇÈí¼þ.lnk
  • %Desktop%\Õ˺ű£ÏÕ¹ñ.lnk
  • %Start Menu%\Internet Explorer.url
  • %Start Menu%\ÌÔ±¦Íø.lnk
  • %Start Menu%\Internet Explorer.html
  • %Start Menu%\Programs\Internet Explorer.url
  • %Start Menu%\Programs\ÌÔ±¦Íø.lnk
  • %Start Menu%\Programs\Internet Explorer.html
  • %User Profile%\Quick Launch\Internet Explorer.url
  • %User Profile%\Quick Launch\ÌÔ±¦Íø.lnk
  • %User Profile%\Quick Launch\Internet Explorer.html
  • %User Profile%\Quick Launch\Æô¶¯ Internet Explorer ä¯ÀÀÆ÷.lnk
  • %User Profile%\Quick Launch\ÈðÐÇɱ¶¾Èí¼þ.lnk
  • %User Profile%\360se\360se_s.ini
  • %User Profile%\×ÀÃæ\Internet Explorer.lnk
  • %User Profile%\×ÀÃæ\ÌÔ±¦É̳Ç.lnk
  • %System%\drivers\etc\hosts

Step 9

Restore these deleted registry keys/values from backup

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

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden
    • SHOWALL
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder
    • SuperHidden
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder
    • HideFileExt
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer
    • TypedUrls
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden
    • NOHIDDEN
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder
    • Hidden


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