Strange messages with attachments through MSN or Windows Live Messenger..?

Just tonight I got a message from my ex (who is one of my contacts on MSN or Windows Live Messenger) saying...

can I throw this picture of us on my facebook.. please?

and there was an attachment that you had to download - I didnt think as it opened as a message from him and hit accept but then half way through the download it was cancelled - I then sent him a message asking what picture and if he wanted it on facebook that I wanted to see what it was - then I realised its spellling was correct and even used punctuation and realised it cant have been him as he is dyslexic and cant spell and never uses punctuation so then I thought maybe it was his housemate or his gf so I sent another message asking who it was and he called my phone and asked what I was talking about.. I told him and he said he had been getting those messages all day from people on his contacts list - anyone know whats going on?? I told him to deny the attachments from now on as will I but dont know what they are

Strange messages with attachments through MSN or Windows Live Messenger..?microsoft downloads

He needs to uninstall and reinstall messenger, and scan his PC for viruses. One of my friends had this problem.

Strange messages with attachments through MSN or Windows Live Messenger..?microsoft word 2003 internet explorer

I get that too from a specific contact

and so did that contact .. until they downloaded the attachment

as soon as you download the attachment an automated bot will log into your account and send this "bot" to others too

basically your ex downloaded the attachments and now sends them too.

it can even sign you in without your knolegde and start sending attachments