WORM_SOHANAD.NZ


 PLATFORM:

Windows 98, ME, NT, 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type:

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This Worm adds registry entries to enable its automatic execution at every system startup.



It connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats.



  TECHNICAL DETAILS

File Size:

267083 bytes

Memory Resident:

Yes

Initial Samples Received Date:

17 Dec 2009


Installation


This Worm drops the following files:

      • %System%\autorun.ini

    (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.)


    It drops the following copies of itself into the affected system:

        • %Windows%\chrome.exe
        • %System%\chrome.exe

      (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.)



      Autostart Technique


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



      Other System Modifications


      This Worm adds the following registry keys:



      Download Routine


      This Worm connects to the following malicious URLs:

          • {BLOCKED}
          • {BLOCKED}
          • {BLOCKED}
          • {BLOCKED}
          • {BLOCKED}
          • {BLOCKED}
          • {BLOCKED}
          • {BLOCKED}
          • {BLOCKED}
          • {BLOCKED}


          SOLUTION


        Step 1


        Terminate the malware/grayware/spyware process:

        [ Learn More ]
        Notes=
      • For Windows 98 and ME users, Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
      • If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
      • If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

      • Step 2


        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.

        • HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\Policies\Explorer
          • NofolderOptions=1
        • HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\Policies\SYSTEM
          • DisableTaskMgr=1
          • DisableRegistryTools=1
        • HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\Windows\CURRENTVERSION\Run\Yahoo Messengger
          • %System%\chrome.exe=REG_SZ


        Step 3


        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.

        • HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\WINDOWS NT\CURRENTVERSION\Winlogon
          • From: Shell=Explorer.exe chrome.exe
            + To: Shell=Explorer.exe
        • HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\Internet Explorer\Main
          • From: Default_Page_URL=http://h1.ripway.com/mygoogle0/index.html
            + To: Default_Page_URL=http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome
          • From: Default_Search_URL=http://h1.ripway.com/mygoogle0/index.html
            + To: Default_Search_URL=http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch
          • From: Search Page=http://h1.ripway.com/mygoogle0/index.html
            + To: Search Page=http://www.microsoft.com/isapi/redir.dll?prd=ie&ar=iesearch
          • From: Start Page=http://h1.ripway.com/mygoogle0/index.html
            + To: Start Page=http://www.microsoft.com/isapi/redir.dll?prd={SUB_PRD}&clcid={SUB_CLSID}&pver={SUB_PVER}&ar=home
        • HKEY_CURRENT_USER\SOFTWARE\MICROSOFT\Internet Explorer\Main
          • From: Start Page=http://h1.ripway.com/mygoogle0/index.html
            + To: Start Page=about:blank


        Step 4


        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%\autorun.ini
        • %Windows%\chrome.exe
        • %System%\chrome.exe

        Note: To do a search for the following files, right-click Start then click Search... or Find..., depending on the version of Windows you are running.For each file to be deleted, type its file name in the Named input box. In the Look In drop-down list, select My Computer, then press Enter.
      • Once located, select the file then press SHIFT+DELETE to permanently delete the file.
      • Repeat the said steps for all files listed.

      • Step 5


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


        *Note: 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.


        Did this description help? Tell us how we did.