W32.Mimail.J@mm

SUMMARY

Due to a decreased rate of submissions, Symantec Security Response has downgraded this threat to a Category 2 rating as of January 6, 2004.

W32.Mimail.J@mm is a mass-mailing worm that attempts to steal personal information. This worm displays a series of forms that ask users to enter their credit card information. (See the "Technical Details" for illustrations.) This information is saved and later emailed to several predetermined email addresses.

This worm is similar to W32.Mimail.I@mm.

The email has the following characteristics:

From: Do_Not_Reply@paypal.com
Subject: IMPORTANT  <random string of characters>
Attachment: InfoUpdate.exe -or-
www.paypal.com.pif

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Note: Virus definitions dated November 17, 2003, rev 21 (20031117.021), or greater are required to detect this threat.

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Antivirus Protection Dates

• Initial Rapid Release version November 17, 2003
• Latest Rapid Release version September 28, 2010 revision 054
• Initial Daily Certified version November 17, 2003
• Latest Daily Certified version September 28, 2010 revision 036
• Initial Weekly Certified release date November 17, 2003

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: More than 1000
• Number of Sites: More than 10
• Geographical Distribution: Medium
• Threat Containment: Easy
• Removal: Moderate

TECHNICAL DETAILS

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

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

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   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.

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2. Adds the value:
   
   "SvcHost32"="%Windir%\svchost32.exe"
   
   to the registry key:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
   
   so that the worm runs when you start Windows.
   
   
3. Displays the following .hta file:
   
   
   
   
   

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   Notes:
   • These are not Web pages, but files that the worm created (C:\pp.hta).
   • As a close button does not exist on the window, press Alt + F4 to close the pages.

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4. A second .hta file is presented after completing the form and clicking Next:
   
   
   
   
   
5. Saves the information entered into the form to the file C:\ppinfo.sys and displays a third .hta file:
   
   
   
   
   
6. Checks for ppinfo.sys, which indicates that the fake PayPal form was completed.
   
   
7. Checks for an active Internet connection by trying to resolve the host name, www.akamai.com. If successful, the worm attempts to send the information in ppinfo.sys to a group of predetermined email addresses.
   
   
8. The worm 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 any discovered email addresses to the file, %Windir%\el388.tmp.
   
   
10. Connects to the SMTP server of the email recipient and sends email each recipient address recorded in el388.tmp.
    
    
11. The email message has the following form:
    
    From: Do_Not_Reply@paypal.com
    Subject: IMPORTANT
    Message:
    Dear PayPal member,
    
    We regret to inform you that your account is about to be expired in next five business days. To avoid suspension of your account you have to reactivate it by providing us with your personal information.
    To update your personal profile and continue using PayPal services you have to run the attached application to this email. Just run it and follow the instructions.
    IMPORTANT! If you ignore this alert, your account will be suspended in next five business days and you will not be able to use PayPal anymore.
    Thank you for using PayPal.
    
    Attachment: www.paypal.com.pif -or-
    InfoUpdate.exe

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.

REMOVAL

Removal using the W32.Mimail Removal Tool
Symantec Security Response has created a tool to remove W32.Mimail.J@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. Do one of the following:
   • Windows 95/98/Me: Restart the computer in Safe mode.
   • Windows NT/2000/XP: End the malicious process.
4. Run a full system scan and delete all the files detected as W32.Mimail.J@mm.
5. Delete the value that was added to the registry.
6. Delete the non-malicious files that W32.Mimail.J@mm left.
   

For specific 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:

• "How to disable or enable Windows Me System Restore"
• "How to turn off or turn on Windows XP System Restore"

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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.

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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 malicious process

Windows 95/98/Me
Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."

Windows NT/2000/XP
To end the malicious 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 svchost32.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.
   • For Norton AntiVirus consumer products: Read the document, "How to configure Norton AntiVirus to scan all files."
   • For Symantec AntiVirus Enterprise products: Read the document, "How to verify that a Symantec Corporate antivirus product is set to scan all files."
2. Run a full system scan.
3. If any files are detected as infected with W32.Mimail.J@mm, click Delete.

5. Deleting the value from the registry

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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.

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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:
   
   "SvcHost32"="%Windir%\svchost32.exe"
   
   
5. Exit the Registry Editor
   
   

6. Deleting the non-malicious files that W32.Mimail.J@mm left
Although these files are not malicious, delete them, if found, as they are associated with the worm:

• %Windir%\zp3891.tmp
• %Windir%\ee98af.tmp
• %Windir%\el388.tmp
• C:\ppinfo.sys
• C:\pp.hta
• C:\pp.gif