Threat Descriptions

Email-Worm:W32/Mimail.J

Classification

Category :

Malware

Type :

Email-Worm

Platform :

W32

Aliases :

Mimail.J

Summary

Mimail.J is an email worm which disguises itself as an email from Paypal on-line payment service and tries to steal credit card information. It arrives with the subject "IMPORTANT" and attachment named www.paypal.com.pif.

Except from some textual content the worm's code is almost exactly the same as Mimail.I

Mimail.I: https://www.f-secure.com/v-descs/mimail_i.shtml

Removal

Manual disinfection of an Mimail.J infected computer consists of the following steps:

1, Remove the registry value

[HKLM\Software\Microsoft\Windows\CurrentVersion\Run\SvcHost32]

2, Restart the computer

3, Delete '%WinDir%\svchost32.exe' (where %WinDir% is the Windows Directory, typically c:\windows\ or c:\winnt).

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

Mimail.J was found on November 17th, 2003. As Mimail.J is packed with a non-modified version of UPX, it is a recompiled version with minimal changes in its code. It arrives in email that looks as follows: 

From: "PayPal.com" Do_Not_Reply@paypal.com
Subject:
IMPORTANT
Attachment: www.paypal.com.pif
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.

Please note that messages received with a subject "Problems with your PayPal account" and attachment named InfoUpdate.exe were seeded by Mimail author. The worm does not use this subject and attachment name when spreading from an infected computer.

The address collection routine is the same as in the previous variant.

The mail spreading routine is the same as in the previous variant.

Payload

Like Mimail.I: The worm displays a fake Paypal form. The form closely resembles the look of PayPal's website. This way the worm tries to fool the users to enter their credit card information, which is mailed to certain email addresses.

This new variant, in addition, asks for personal information in a form like shown below:

System Infection

Same as in Mimail.I