These trojans pick a random entry from the infected address book and send themself to every other entry.
So the only thing known for sure is that both you and 'Terry' are in the address book of the person who
does have the virus. Probably a PPruNer too.
Since it looks like you have been 'selected' as the from address, you can probably expect some more undeliverable mail messages. I got similarly hijacked without ever being infected a while back. Took about a week before the fallout subsided.
Pr!cks !
