Discovered: November 13, 2003
Updated: February 13, 2007 12:13:51 PM
Also Known As: W32.Paylap@mm, W32.Mimail.H@mm, W32/Mimail-I [Sophos], WORM_MIMAIL.I [Trend], Win32.Mimail.I [Computer Assoc, W32/Mimail.i@MM [McAfee], I-Worm.Mimail.i [Kaspersky]
Type: Worm
Systems Affected: Windows

W32.Mimail.I@mm is a mass-mailing worm that attempts to steal credit card information. The worm displays a form that asks the user to enter their credit card information. (See the "Technical Details" section for an illustration of a fake "PayPal Secure Application" window.) This information is saved and later emailed to several predetermined email addresses.

The email has the following characteristics:

Attachment: paypal.asp.scr -or-

Note: Virus definitions dated prior to November 17, 2003 may detect this threat as W32.Paylap@mm or W32.Mimail.H@mm.

Antivirus Protection Dates

  • Initial Rapid Release version November 13, 2003
  • Latest Rapid Release version May 31, 2016 revision 036
  • Initial Daily Certified version November 13, 2003
  • Latest Daily Certified version June 01, 2016 revision 005
  • Initial Weekly Certified release date November 13, 2003

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

Technical Description

When W32.Mimail.I@mm is executed, it does the following:

  1. Copies itself as %Windir%\svchost32.exe and %Windir%\ee98af.tmp.

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

  2. Adds the value:


    to the registry key:


    so that the worm runs when you start Windows.

  3. Displays the following .hta file:

    Note: This is not a Web page, but a file that the worm created (C:\pp.hta).

  4. Saves the information entered into the form to the file C:\ppinfo.sys.

  5. Checks for an active Internet connection by trying to resolve the host name

  6. Checks for the file "ppinfo.sys," which indicates that the fake PayPal form was completed.

  7. Sends this information to four predetermined email addresses.

  8. Searches for email addresses in cached Internet files, except for those with the following extensions:
      • com
      • wav
      • cab
      • pdf
      • rar
      • zip
      • tif
      • psd
      • ocx
      • vxd
      • mp3
      • mpg
      • avi
      • dll
      • exe
      • gi
      • jpg
      • bmp

  9. Saves the addresses discovered in the file %Windir%\el388.tmp.

  10. Connects to an SMTP server and sends email to the addresses it found.

    The email has the following form:

    Attachment: paypal.asp.scr -or-

    Dear PayPal member,

    PayPal would like to inform you about some important information regarding your PayPal account. This account, which is associated with the email address


    will be expiring within five business days.  We apologize for any inconvenience that this may cause, but this is occurring because all of our customers are required to update their account settings with their personal information.

    We are taking these actions because we are implementing a new security policy on our website to insure everyone's absolute privacy. To avoid any interruption in PayPal services then you will need to run the application that we have sent with this email (see attachment) and follow the instructions. Please do not send your personal information through email, as it will not be as secure.

    IMPORTANT! If you do not update your information with our secure application within the next five business days then we will be forced to deactivate your account and you will not be able to use your PayPal account any longer. It is strongly recommended that you take a few minutes out of your busy day and complete this now.

    DO NOT REPLY TO THIS MESSAGE VIA EMAIL! This mail is sent by an automated message system and the reply will not be received.

    Thank you for using PayPal.


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.


Removal using the W32.Mimail Removal Tool
Symantec Security Response has created a tool to remove W32.Mimail.I@mm, which is the easiest way to remove this threat. Read the document, W32.Mimail Removal Tool , for instructions on how to use this tool.

Manual Removal
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. Restart the computer in Safe mode or VGA mode.
  4. Run a full system scan and delete all the files detected as W32.Mimail.I@mm. Delete the nonviral files dropped by the worm.
  5. Reverse the changes 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:
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. 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 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. 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. If any files are detected as W32.Mimail.I@mm, click Delete.
  4. Delete the following files if they exist (These files are not viral, and thus, Symantec antivirus products do not detec them):
    • %Windir%\el388.tmp
    • C:\ppinfo.sys
    • C:\pp.hta
    • C:\pp.gif

Note: The worm contains references to a file named zp3891.tmp. The worm attempts to delete this file if it exists, but does not appear to create a file by this name. Delete %Windir%\zp3891.tmp if you find it.

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:


  4. In the right pane, delete the value:


  5. Exit the Registry Editor.

Writeup By: Heather Shannon