Classification

Category :

Malware

Type :

-

Aliases :

Memas, I-Worm.Memas, W32/Memas@mm, W32.Memas@mm

Summary

Memas is a 2-component email worm. It is also capable of infecting executable files. The worm spreads itself as an executable attachment in emails that are sent to all email addresses from an infected computer's Address Book.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

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

Memas worm usually arrives as an executable email attachment. When the worm's file is run, it drops a Visual Basic script file as C:\FEMAIL.VBS and activates it.

The Visual Basic Script part is the one that does the mass mailing of the worm. It first check for the presence of a Windows registry key:

[HKCU\Software\Microsoft\Windows\CurrentVersion\MeMeMasr?]

and if it does not exist, it creates such key. Thus the worm will mass mail once per infected computer.

Next, it uses Outlook Application to get all addresses from the address book and mass mail a copy of the worm in messages that look as follows:

     Subject: "Hi Friend"         Body: "Please See The Attachment"         Attachment:  		  

The <worm's file name> is the name of the worm's file that depends on the name of the infected attachment that was originally run by a user.

To hide this action the Visual Basic Script deletes all sent emails.

The worm is capable of infecting executable files on an infected computer. It scans all available drives and prepends itself to all found executable files. However, the worm does not infect files in folders that have the following names:


 Subject: "Hi Friend"
 Body: "Please See The Attachment"
 Attachment:
		

The worm also doesn't infect files with the following names:


 Subject: "Hi Friend"
 Body: "Please See The Attachment"
 Attachment:
		

All infected files are marked by adding the 'ShohdiEmail' line to their ends. When an infected file is run, the worm takes control, extracts the original file's contents to the same folder, but with .SEL extension and runs the extracted file.

The worm can display a mixed English-Arabic message.