Summary

X97M/Papa is an Excel 97 macro worm. It's quite similar to the widespread W97M/Melissa virus, but is probably not written by the same writer.

Additional Details

The Papa.A variant has a serious bug in it's code and it does not work. This bug was fixed in the Papa.B variant which is able to spread via Internet.

Every time when a XLS file infected by Papa is opened, it e-mails a copy of itself via e-mail, using Microsoft Outlook, to the first 60 people in the Address Book.

The e-mail sent by the worm looks like this:

        From: (name of infected user)
        To: (60 names from alias list of the infected user)
        Subject: Fwd: Workbook from all.net and Fred Cohen

        Urgent info inside.  Disregard macro warning.

        Attachment: XPASS.XLS

If the attached file is opened, it looks like this:



It is important to notice that Dr. Fred Cohen and the website at all.net have nothing to do with the worm. Authors of this worm simply want to harass him. In addition, the worm will try to overload the all.net web server by repeatedly pinging it.

The worm won't spread further to other XLS files, it just mails XPASS.XLS around.

[Analysis: Mikko Hypponen and Katrin Tocheva, F-Secure]