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  3. W32.HLLW.Lovgate.C@mm

W32.HLLW.Lovgate.C@mm

Risk Level 2: Low

Discovered:
February 24, 2003
Updated:
February 13, 2007 11:43:24 AM
Also Known As:
WORM_LOVGATE.C [Trend], Win32/Lovgate.C@mm [RAV], W32/Lovgate.c@M [McAfee], I-Worm.Supnot.c [KAV], W32/Lovgate-B [Sophos], Win32.Lovgate.C [CA]
Type:
Worm
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows XP

When W32.HLLW.Lovgate.C@mm is executed, it performs the following actions:
  1. Copies itself to the %System% folder as:
    • WinRpcsrv.exe
    • Syshelp.exe
    • Winrpc.exe
    • WinGate.exe
    • Rpcsrv.exe

      NOTE: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).

  2. If the infected computer is running Windows 95/98/Me, it adds:

    run=rpcsrv.exe

    to the [windows] section in the Win.ini file.
  3. Copies the following files to the %System% folder, and then executes them:
    • ily.dll
    • Task.dll
    • Reg.dll
    • 1.dll

      NOTE: These files are the Backdoor Trojan components of W32.HLLW.Lovgate.C@mm. Symantec antivirus products detect them as Backdoor.Trojan.

  4. Adds the values:

    syshelp                    %system%\syshelp.exe
    WinGate initialize         %system%\WinGate.exe -remoteshell
    Module Call initialize     RUNDLL32.EXE reg.dll ondll_reg


    to the registry key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
  5. Modifies the default value of the following registry key:

    HKEY_CLASS_ROOT\txtfile\shell\open\command

    to:

    winrpc.exe %1
  6. Copies itself to all the network-shared folders and subfolders as any of the following:
    • Pics.exe
    • Images.exe
    • Joke.exe
    • Pspgame.exe
    • News_doc.exe
    • Hamster.exe
    • Tamagotxi.exe
    • Searchurl.exe
    • Setup.exe
    • Card.exe
    • Billgt.exe
    • Midsong.exe
    • S3msong.exe
    • Docs.exe
    • Humor.exe
    • Fun.exe

  7. Listens on TCP port 10168 and notifies the hacker using email at one of the following addresses:
    • hacker117@163.com
    • hello_dll@163.com

      The worm has a password authentication routine. After entering the correct password, the worm will start a command shell for the hacker.

  8. Searches the following folders:
    • .\ (This is the folder from which the worm was executed.)
    • winpath
    • The folder listed in the following registry value:

      HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\
      Explorer\Shell Folders\Personal


  9. If the worm finds any files in the aforementioned folders, whose extension starts with "ht," it will attempt to get all the email addresses from the files, create an email with an attachment infected with W32.HLLW.Lovgate.C@mm, and then send the infected email to the email addresses in the .ht* file.
  10. Attempts to reply to all the incoming messages when they arrive in the mailbox of certain MAPI-compliant email clients, including Microsoft Outlook. Due to a bug in the code, the email may not be successfully delivered.
    If the original email is:
    Subject: <subject>
    From: <username>@<hostname>
    Message: <original message body>

    the worm will attempt to send the following email:

    Subject: Re: <subject>
    To: SMTP:<someone>@<somewhere.com>
    Message:
    '<someone>' wrote:
    ===
    > <original message body>
    >
    ===

    <somewhere.com> account auto-reply:

     ' I'll try to reply as soon as possible.
     Take a look to the attachment and send me your opinion! '


         > Get your FREE <somewhere.com> account now! <


    The attachment sent with the email has a filename, which is chosen from the same list used by the worm in its network-propagation routine. For example, the filename could be one of the following:
    • Pics.exe
    • Images.exe
    • Joke.exe
    • Pspgame.exe

      For the complete list, refer to step 6 of this section.

Additional actions on NT/2000/XP
If the infected computer runs Windows NT, 2000, or XP, the worm will perform the following actions:
  1. Copies itself as %System%\Ssrv.exe.

    NOTE: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
  2. Creates the registry key:

    HKEY_LOCAL_MACHINE\Software\KittyXP.sql\Install
  3. Adds the value:

    run              rpcsrv.exe

    to the registry key:

    HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
  4. Creates the registry key:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\dll_reg
  5. Adds the value:

    dll.reg rundll32.exe taskdll ondll_reg server
  6. If the worm detects the process Lsass.exe, it attempts to create a remote thread in that particular process and inject a hook to 1.dll
  7. Injects another thread into Lsass.exe, which creates a listening server on TCP port 20,168. This server gives anyone remote access without any authentication.
  8. Starts the Backdoor Trojan component as the service, "Windows Management Extension," which listens on TCP port 1192.
  9. Scans all the computers on the local network and uses the following passwords to attempt to log in as "Administrator:"
    • <empty.password>
    • 123
    • 321
    • 123456
    • 654321
    • guest
    • administrator
    • admin
    • 111111
    • 666666
    • 888888
    • abc
    • abcdef
    • abcdefg
    • 12345678
    • abc123

      NOTE: <empty.password> is a variable, which is an empty password.

  10. If the worm successfully logs on to a remote computer, it attempts to copy itself as:

    \\<remote.computer.name>\admin$\system32\stg.exe

    And then, it attempts to start the file on the remote computer as the service, "Microsoft NetWork Services FireWall."

    NOTE: <remote.computer.name> is a variable, which refers to the name of the remote computer.

Email Routine Details

To replicate, the worm uses its own SMTP engine to create email messages, add infected attachments to the email, and then mass mail the infected email messages. The email message is one of the following:

Subject: Documents
Attachment: Docs.exe
Message:: Send me your comments...

or:

Subject: Roms
Attachment: Roms.exe
Message:: Test this ROM! IT ROCKS!.

or:

Subject: Pr0n!
Attachment: Sex.exe
Message:: Adult content!!! Use with parental advisory.

or:

Subject: Evaluation copy
Attachment: Setup.exe
Message:: Test it 30 days for free.

or:

Subject: Help
Attachment: Source.exe
Message:: I'm going crazy... please try to find the bug!

or:

Subject: Beta
Attachment: _SetupB.exe
Message:: Send reply if you want to be official beta tester.

or:

Subject: Do not release
Attachment: Pack.exe
Message:: This is the pack ;)

or:

Subject: Last Update
Attachment: LUPdate.exe
Message:: This is the last cumulative update.

or:

Subject: The patch
Attachment: Patch.exe
Message:: I think all will work fine.

or:

Subject: Cracks!
Attachment: CrkList.exe
Message:: Check our list and mail your requests!


Symantec ManHunt
To specifically detect this threat as W32.HLLW.Lovgate.C@mm, Symantec recommends that you use a Symantec ManHunt product to activate the HYBRID MODE function and apply the following custom rules:

*******************start file********************

alert tcp any 10168 -> any any (msg:"W32.HLLW.Lovgate.C@mm backdoor login attempt"; content:"Sorry, Your PassWord Not Right.";)

*************EOF*********************

will trigger on unsuccessful login attempts by the hacker and

*******************start file********************

alert tcp any 10168 -> any any (msg:"W32.HLLW.Lovgate.C@mm backdoor login success"; content:"OK! Please Enter:";)

*************EOF*********************

will trigger on successful login attempts by the hacker. For more information on how to create custom signatures, refer to the "Symantec ManHunt Administrative Guide: Appendix A Custom Signatures for HYBRID Mode."

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.
Writeup By: Tony Conneff
Summary| Technical Details| Removal

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