I have a client that uses a hotmail email address. He uses outlook to handle this account. Recently there has been emails sent, with no subject, to several contacts in his contact list, me being one of them. It contains a link to a website (different sites) and I expect they are pornographic, but haven't opened any.
Typically I would think someone is just spoofing him, but these email show up in his "Sent" folder in hotmail. I looked at the header info (included in an attachment) and it shows a reply address different than email sent from his Outlook account. The reply address is the one he has set up in his hotmail account settings. To test, I sent an email from his outlook, and one from webmail (hotmail). only the one from webmail showed that reply address. I looked at the originating IP and they are from a couple of places in Europe.
I recommend he change the password on his hotmail account but am wondering if someone is getting information with a trojan or something like that. I find it odd that they only send to several people, and that it's only occurred 4 times in the last couple of months.