Summary

This worm is able of spreading through e-mail sending messages with different content. It has, as well, capability to spread through Kazaa's P2P network.

Additional Details

The worm has three components, it was written in Visual Basic and packed with UPX. The first component if the one responsible for the installation into the system, it's an UPX file of length 9266 (24626 unpacked). The second component contains the main set of functionalities of the worm, the e-mail sending code. The third component is an UPX packed copy of the SMTP Control for Visual Basic. Which the worm will use to send the e-mail.

Installation to system

It will drop its components into the default temporary folder as:

 explore.exe (main component)
 a.exe (installation component)
 smtp.ocx (SMTP Control for Visual Basic)

All of the components will also be copied to the System32 windows folder. And will copy the installation component with the additional names:

 a.bat
 a.com
 a.pif
 a.scr

P2P spreading

This worm will also read from the Windows registry the location of the Kazaa downloads folder and copy itself to that location.

Mass mailing

It will extract e-mail addresses from files in the users' computer which have one of the following extensions:

 .htm
 .html
 .eml
 .txt

The messages sent by the worm will have the following characteristics:

Subjects are chosen from:

 Check this out ;)", <>)
 Enjoy!
 This is all i can send
 Have Fun :)
 You gonna love it
 Here is what u wanted
 ;)
 Wait for more :)
 looool
 Take a look
 Never mind !
 Attatchments
 See the attatched file", <>)
 gift :)
 Surprise!
 save it for hard times
 Happy Times :)
 Useful
 Very funny
 Try it
 you have to see this!
 emazing!

To which "Fw:" or "Re:" can be prepended.

Payload

Internet Explorer start page is set to:

 http://www.geocities.com/yori_mrakkadi

Detection

Detection in F-Secure Anti-Virus was published on October 15th, 2003 in update:

[FSAV_Database_Version]
Version=2003-10-15_02

Write-up: Ero Carrera, October 31st, 2003;

Technical Details: Ero Carrera, October 31st, 2003;