Downloader.Lunii

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Discovered: October 04, 2004
Updated: February 13, 2007 12:28:03 PM
Type: Trojan Horse
Systems Affected: Windows


Downloader.Lunii is a Trojan horse program that attempts to download remote files, terminate adware products, and delete files.



Removing entries from the Hosts file
If this threat has modified the Windows Hosts file, you will no longer be able to open any of the sites mentioned in step 6 of the "Technical Details" section. These sites appear to be mostly adult content-related or under construction.

If you need access to these sites, and the entries that are added to the Hosts file are blocking them, you can edit the Hosts file and remove them.



To edit the Hosts file and remove all the entries that the worm added

Note: The location of the Hosts file may vary and some computers may not have this file. For example, if the file exists in Windows 98, it will usually be in C:\Windows; and it is located in the C:\WINNT\system32\drivers\etc folder in Windows 2000. There may also be multiple copies of this file in different locations.


Follow the instructions for your operating system:

  • Windows 95/98/Me/NT/2000
    1. Click Start, point to Find or Search, and then click Files or Folders.
    2. Make sure that "Look in" is set to (C:) and that "Include subfolders" is checked.
    3. In the "Named" or "Search for..." box, type:

      hosts

    4. Click Find Now or Search Now.
    5. For each Hosts file that you find, right-click the file, and then click Open With.
    6. Deselect the "Always use this program to open this program" check box.
    7. Scroll through the list of programs and double-click Notepad.
    8. When the file opens, delete all the entries in step number 6 of the "Technical Details" section.
    9. Close Notepad and save your changes when prompted.

  • Windows XP
    1. Click Start > Search.
    2. Click All files and folders.
    3. In the "All or part of the file name" box, type:

      hosts

    4. Verify that "Look in" is set to "Local Hard Drives" or to (C:).
    5. Click More advanced options.
    6. Check Search system folders.
    7. Check Search subfolders.
    8. Click Search.
    9. Click Find Now or Search Now.
    10. For each Hosts file that you find, right-click the file, and then click Open With.
    11. Deselect the Always use this program to open this program check box.
    12. Scroll through the list of programs and double-click Notepad.
    13. When the file opens, delete all the entries in step number 6 of the "Technical Details" section.
    14. Close Notepad and save your changes when prompted.


Antivirus Protection Dates

  • Initial Rapid Release version October 04, 2004
  • Latest Rapid Release version March 23, 2017 revision 037
  • Initial Daily Certified version October 04, 2004
  • Latest Daily Certified version March 23, 2017 revision 041
  • Initial Weekly Certified release date October 06, 2004

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Writeup By: Hiroshi Shinotsuka

Discovered: October 04, 2004
Updated: February 13, 2007 12:28:03 PM
Type: Trojan Horse
Systems Affected: Windows


When Downloader.Lunii is executed, it performs the following actions:

  1. Downloads and executes the following files:
    • %Windir%\toolbar.exe
    • %Windir%\mstasks1.exe
    • %system%\dktime.exe
    • %system%\dk.exe
    • %system%\dk32.exe
    • %system%\sexxx.exe

      Notes:
    • %System% is a variable that refers to the System folder. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).
    • %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows (Windows 95/98/Me/XP)or C:\Winnt (Windows NT/2000).

  2. Terminates the following process, which may be related to adware programs:
    • lpt.exe
    • ir.exe
    • intron.exe
    • intronet.exe
    • twink64.exe
    • usb.exe
    • teur.exe
    • host32.exe
    • sidefind.exe
    • alchem.exe
    • powerscan.exe
    • bdl74125.exe
    • Installer2.exe
    • ttgkirnl.exe
    • bargains.exe
    • WinClt.exe
    • Winad.exe
    • istsvc.exe
    • actalert.exe
    • optimize.exe
    • iinstall.exe
    • fnnmqi.exe
    • exdl.exe
    • printer.exe
    • printer32.exe
    • ykyrtws.exe
    • loadclean.exe
    • telnet.exe

  3. Deletes the following files, which may be related to adware programs:
    • %Temp%\bdl74125.exe
    • %Temp%\Installer2.exe
    • %Temp%\msbb.exe
    • %System%\host32.exe
    • %System%\telnet.exe.tmp
    • %System%\mouse.exe
    • %System%\com.exe
    • %System%\fnnmqi.exe
    • %System%\exdl.exe
    • %System%\exe2bin.exe
    • %System%\exul.exe
    • %System%\fastopen.exe
    • %System%\mscdexnt.exe
    • %System%\printer.exe
    • %System%\printer32.exe
    • %System%\ykyrtws.exe
    • %System%\lpt.exe
    • %System%\ir.exe
    • %System%\intron.exe
    • %System%\intronet.exe
    • %System%\twink64.exe
    • %System%\usb.exe
    • %Windir%\alchem.exe
    • %Windir%\adp8027_ISEARCHTECH5.exe
    • %Windir%\preInsTT.exe
    • %Windir%\preInsln.exe
    • %Windir%\preInMPP.exe
    • %Windir%\loadclean.exe

      Note: %Temp% is a variable that refers to the Windows temporary folder. By default, this is C:\Windows\TEMP (Windows 95/98/Me/XP) or C:\WINNT\Temp (Windows NT/2000).

  4. Deletes the following values:
    • "Ukbybc"
    • "ControlPanel"
    • "alchem"
    • "BullsEye Network"
    • "dmesewxqtj"
    • "Internet Optimizer"
    • "IST Service"
    • "Power Scan"
    • "Winad Client"

      from the registry key:

      HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

      to prevent certain programs from being executed when Windows starts.

  5. Deletes all the registry entries under the following registry key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
    Explorer\Browser Helper Objects

    to delete certain Browser Helper Objects.

  6. Overwrites the Hosts file with the following text, which blocks access to certain Web sites:

    127.0.0.3 allforadult.com
    127.0.0.3 www.allforadult.com
    127.0.0.3 www.iframe.biz
    127.0.0.3 iframe.biz
    127.0.0.3 www.newiframe.biz
    127.0.0.3 newiframe.biz
    127.0.0.3 www.vesbiz.biz
    127.0.0.3 vesbiz.biz
    127.0.0.3 www.pizdato.biz
    127.0.0.3 pizdato.biz
    127.0.0.3 www.aaasexypics.com
    127.0.0.3 aaasexypics.com
    127.0.0.3 www.virgin-tgp.net
    127.0.0.3 virgin-tgp.net


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: Hiroshi Shinotsuka

Discovered: October 04, 2004
Updated: February 13, 2007 12:28:03 PM
Type: Trojan Horse
Systems Affected: Windows


The following instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

Important: On computers running Norton AntiVirus 2005 or later, the QuickScan tool will automatically search for and remove malicious threats when new virus definitions are downloaded. While every effort has been made to ensure that the QuickScan tool removes all the traces of a malicious threat from an infected computer, we advise that you confirm that all the files and registry entries have been removed. We recommend following the manual removal steps and deleting any threat-related files or registry entries remaining on the computer.

  1. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Restart the computer in Safe mode or VGA mode.
  4. Run a full system scan and delete all the files detected as Downloader.Lunii.
For details on each of these steps, read the following instructions.

1. To disable System Restore (Windows Me/XP)
If you are running Windows Me or Windows XP, we recommend that you temporarily turn off System Restore. Windows Me/XP uses this feature, which is enabled by default, to restore the files on your computer in case they become damaged. If a virus, worm, or Trojan infects a computer, System Restore may back up the virus, worm, or Trojan on the computer.

Windows prevents outside programs, including antivirus programs, from modifying System Restore. Therefore, antivirus programs or tools cannot remove threats in the System Restore folder. As a result, System Restore has the potential of restoring an infected file on your computer, even after you have cleaned the infected files from all the other locations.

Also, a virus scan may detect a threat in the System Restore folder even though you have removed the threat.

For instructions on how to turn off System Restore, read your Windows documentation, or one of the following articles:

Note:
When you are completely finished with the removal procedure and are satisfied that the threat has been removed, re-enable System Restore by following the instructions in the aforementioned documents.

For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article, "Antivirus Tools Cannot Clean Infected Files in the _Restore Folder," Article ID: Q263455.

2. To update the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:

  • Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted daily. You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).

    The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

    Note: If you see an error, such as LU1418, when you try to run LiveUpdate and you cannot get the Web site hosting the Intelligent Updater, it is likely that the worm has modified the Hosts file. You can either download and install LiveUpdate 2.5, which can remove Symantec entries from that file, or you can edit it yourself. See the instructions for both in the "Additional Information" section below.

3. To restart the computer in Safe mode or VGA mode

Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.
  • For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
  • For Windows NT 4 users, restart the computer in VGA mode.
4. To scan for and delete the infected files
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
  2. Run a full system scan.
  3. If any files are detected as infected with Downloader.Lunii, click Delete.


Writeup By: Hiroshi Shinotsuka