1) Useful fact to remember: Viruses typically forge
the From: address.
2) Sending forged email is exceedingly easy.
3) Another useful thing: The phys-l archives are
searchable. No attachments appear in the archives. So
there is every reason to believe that the listserv
has *not* been involved in propagating any viruses or
worms.
4) We can surmise with modest confidence that someone
who is infected lists both Ludwik and phys-l in his
address book. The rationale here is that the address
book is the worm's typical source of recipient-addresses
and (forged!) sender-addresses. But even this is a
moving target, since worms are getting cleverer about
how they make up addresses.