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Discovered: July 13, 2002
Updated: February 13, 2007 11:59:36 AM
Type: Worm
Systems Affected: Windows

W32.Netlip.Worm is a worm that attaches itself to email messages each time that you send email to anyone from an infected computer. The email has following characteristics:

Attachment: PUBLINet.exe

W32.Netlip.Worm is written in the Microsoft Visual Basic (VB) programming language and is compressed using PELOCK.

Antivirus Protection Dates

  • Initial Rapid Release version July 15, 2002
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version July 15, 2002
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date July 17, 2002

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

Writeup By: Yana Liu

Discovered: July 13, 2002
Updated: February 13, 2007 11:59:36 AM
Type: Worm
Systems Affected: Windows

When you execute the PUBLINet.exe attachment, W32.Netlip.Worm does the following:

It first installs itself on the system.

It then displays these messages:

Next, it copies itself as:

  • C:\%windir%\PUBLINet.exe
  • C:\%windir%\Sicom.exe

It also copies:


  • C:\%system%\Wsock32.old
  • C:\%windir%\Wsock32.dll

%Windir% is a variable. The worm locates the \Windows folder (by default, this is C:\Windows or C:\Winnt) and copies a file to that location.
%System% is a variable too. The worm locates the \Windows\System folder (by default this is C:\Windows\System or C:\Winnt\System32) and copies a file to that location.

Then it modifies C:\%windir%\Wsock32.dll by hooking the send() function of Wsock32.dll As a result, the worm's hooked routine gets control each time that you communicate over the Internet using this send() function.

Next, the worm creates C:\%windir%\Wininit.ini with the following section:


As a result, the next time that you start Windows, C:\%system%\Wsock32.dll is replaced with C:\%windir%\Wsock32.dll

The worm adds the value

Sicom C:\%Windir%\Sicom.exe

to the registry key


This causes the worm to run when you restart Windows.

The worm adds the subkey SICOM to the registry key


and adds the following value to this subkey:

instalado si

During installation, two hidden files are created in the root of drive C:
  • C:\Config._0_
  • C:\Config._1_

Config._0_ is the encrypted email message that contains the MIME-encoded worm. Each time that you send an email message, the worm captures the contents of the message and saves it to the Config._1_ file. the worm reads and decrypts Config._0_ , and then attaches the decrypted Config._0_ to the email. The worm sets the subject line of the message to:


and sends the message.

Finally, the worm sends one more message to the attacker's email address (sicom_bolivia@hotmail.com), which has the following characteristics:

Subject:  PUBLINet reportandose :)
Attachment: <previously captured user's email>

As a result, confidential information might be sent to the attacker.


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: Yana Liu

Discovered: July 13, 2002
Updated: February 13, 2007 11:59:36 AM
Type: Worm
Systems Affected: Windows

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Update the virus definitions, run a full system scan, and delete all files that are detected as W32.Netlip.Worm.
  2. Delete C:\Config._0_ and C:\Config._1_.
  3. Delete the \SICOM subkey under

  4. Delete the value

    Sicom C:\%Windir%\Sicom.exe

    from the registry key

  5. Remove the lines


  from the C:\%windir%\Wininit.ini file.

For details on how to do this, read the following instructions.

To scan for and delete the infected files:
  1. Obtain the most recent virus definitions. There are two ways to do this:
    • Run LiveUpdate. LiveUpdate is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
    • Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions have undergone full quality assurance testing by Symantec Security Response. They are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.

      Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.
  2. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files.
  3. Run a full system scan.
  4. Delete all files that are detected as W32.Netlip.Worm.
  5. Using Windows Explorer, delete the files C:\Config._0_ and C:\Config._1_.

To remove the keys or values that the worm added to the registry :

CAUTION : Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.
  1. Click Start, and click Run. The Run dialog box appears.
  2. Type regedit and then click OK. The Registry Editor opens.
  3. Navigate to and select the following key:

  4. In the right pane, delete the following value:

    Sicom C:\%Windir%\Sicom.exe
  5. Navigate to and select the following key:

  6. Delete the \SICOM subkey.
  7. Exit the Registry Editor.

To remove the line that the worm added to the Wininit.ini file:
  1. Click Start, and click Run.
  2. Type the following, and then click OK.

    edit c:\windows\wininit.ini

    The MS-DOS Editor opens.

    NOTE: If Windows is installed in a different location, make the appropriate path substitution.
  3. Look for the following lines:

  4. Select these three lines. Be sure that you have not selected any other text, and then press Delete.
  5. Click File, and click Save.
  6. Click File, and click Exit.

Writeup By: Yana Liu