Summary

The Sober.W worm was found on November 15th, 2005. This Sober variant is similar to Sober.T, that appeared yesterday:

http://www.f-secure.com/v-descs/sober_t.shtml

Like the previous variants, this one sends itself inside a ZIP archive as an attachment in e-mail messages with English or German texts. We also received several different droppers for this worm variant. They were apparently created by the worm author manually. They are all detected as 'Sober.w' or 'Sober.W.dr'.

Additional Details

This Sober variant sends a bit different e-mail messages:

Subject:

 Ihre eMail!

Body:

 Guten Tag,

 jemand schickte mir eine Mail mit einer Excel oder Access
 Tabelle (kenne mich da nicht so aus!).

 Jedenfalls ist diese Mail aber an ihre Mail Adresse adressiert,
 aber zu meiner gekommen??? Ist wohl irgendein Fehler.

 Ok, hier haben Sie sie wieder zurueck!

Attachment name starts with:

 Tabelle

---- OR ----

Subject:

 Your email

Body:

 Hello,
 Sorry, sorry sorry, because,, my English is not the best!

 ok, I've got an email with an Excel-Table. But I am not the
 recipient, the recipient are you!
 I think, it's an mail error!
 OK, here is your table back!

 cya....

Attachment:

 excel_table.zip

Detection

Sober.W worm is detected with the following F-Secure Anti-Virus updates:

Version=2005-11-15_02

Writeup: Alexey Podrezov; November 15th, 2005;