W32.HLLP.Spreda.B

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Discovered: September 26, 2003
Updated: February 13, 2007 12:08:06 PM
Also Known As: W32.HLLP.Savno, W32/HLLP.Savno!p2p [McAfee], Win32.HLLP.Savno [KAV]
Type: Virus
Systems Affected: Windows


W32.HLLP.Spreda.B is a high-level language virus that spreads through KaZaA networks by infecting the .exe files in the KaZaA download folder. Under some conditions, W32.HLLP.Spreda.B inserts a password stealer onto the system.

NOTE: Virus definitions dated prior to September 30, 2003 may detect this worm as W32.HLLP.Savno.

Antivirus Protection Dates

  • Initial Rapid Release version September 29, 2003
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version September 29, 2003
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date October 01, 2003

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

Writeup By: Atli Gudmundsson

Discovered: September 26, 2003
Updated: February 13, 2007 12:08:06 PM
Also Known As: W32.HLLP.Savno, W32/HLLP.Savno!p2p [McAfee], Win32.HLLP.Savno [KAV]
Type: Virus
Systems Affected: Windows


Once W32.HLLP.Spreda.B is activated, it creates the folder %Windir%\Winww.


Note: %Windir% is a variable. The virus locates the Windows installation folder (by default, this is C:\Windows or C:\Winnt) and copies itself to that location.


Infection
W32.HLLP.Spreda.B infects any .exe files it finds in the KaZaA download folder, if the files are larger than 102,400 bytes and smaller than 10,385,024 bytes.

Insertion
If the file %Windir%\Winset.ini does not exist, W32.HLLP.Spreda.B does the following:
  1. Creates %Windir%\Winset.ini.

  2. Searches for a file named <file name>.url in the folders:

    C:\Document and Settings
    %Windir%\Temporary Internet Files

    where <file name> includes one of the following:

    password
    log on
    log-on
    logon
    login
    bank
    sign-on
    sign on
    building society
    registration
    register
    lloyds

    And if such a file exists, it will drop the %Windir%\Savenow.exe file and create the registry value:

    "Savenow"="%windir%\savenow.exe"

    under the registry key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

    so that Savenow.exe is executed each time you start Windows.
Original host
Next, W32.HLLP.Spreda.B writes the original host to %Windir%\winww\Sn??.exe, where ?? is in the range 00 up to and including 50.

If fewer than 50 infected hosts have been executed, the worm will execute the original host %Windir%\Winww\Sn??.exe.

Savenow.exe
Savenow.exe is a password stealer that, once activated, deletes all the Sn??.exe files from: %Windir%\Winww, and then searches periodically for Internet Explorer windows, where the title bar includes one of the following:

password
log on
log-on
logon
login
bank
sign-on
sign on
building society
registration
register
lloyds

If found, Savenow.exe will grab the URL displayed in that window, and then send it to an Internet site using a standard HTTP request.

Savenow.exe is detected as W32.HLLP.Spreda.B.spy.


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: Atli Gudmundsson

Discovered: September 26, 2003
Updated: February 13, 2007 12:08:06 PM
Also Known As: W32.HLLP.Savno, W32/HLLP.Savno!p2p [McAfee], Win32.HLLP.Savno [KAV]
Type: Virus
Systems Affected: Windows


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

  1. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Do one of the following:
    • Windows 95/98/Me: Restart the computer in Safe mode.
    • Windows NT/2000/XP: End the Trojan process.
  4. Run a full system scan, repair any files detected as W32.HLLP.Spreda.B, and then delete the files detected as W32.HLLP.Spreda.B.spy.
  5. Reverse the changes that the Trojan made to the registry.
For details on each of these steps, read the following instructions.

1. Disabling 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:
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. Updating 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 on U.S. business days (Monday through Friday). 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.

3. Restarting the computer in Safe mode or ending the Trojan process
    Windows 95/98/Me
    Restart the computer in Safe mode. All the Windows 32-bit operating systems, except for Windows NT, can be restarted in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."

    Windows NT/2000/XP
    To end the Trojan process:
    1. Press Ctrl+Alt+Delete once.
    2. Click Task Manager.
    3. Click the Processes tab.
    4. Double-click the Image Name column header to alphabetically sort the processes.
    5. Scroll through the list and look for Savenow.exe.
    6. If you find the file, click it, and then click End Process.
    7. Exit the Task Manager.
4. Scanning for and deleting 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. Repair any files detected as W32.HLLP.Spreda.B, and then delete the files detected as W32.HLLP.Spreda.B.spy.

5. Reversing the changes made to the registry


WARNING: Symantec strongly recommends that you back up the registry before making any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify the specified keys only. Read the document, "How to make a backup of the Windows registry ," for instructions.

  1. Click Start, and then click Run. (The Run dialog box appears.)
  2. Type regedit

    Then click OK. (The Registry Editor opens.)

  3. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

  4. In the right pane, delete the value:

    "Savenow"="%windir%\savenow.exe"

  5. Exit the Registry Editor.


Writeup By: Atli Gudmundsson