How do you work POP3 with hotmail?

How do Hotmail based viruses work?

• My wife's Hotmail account seems to have been infected by one of those viruses that mails a web-link to all your contacts. She picked it up after clicking the link on a similar mail from one of her friends. How does this kind of thing usually work? Does this imply that a program was downloaded and installed onto her machine and is running there? (She's using Windows and accessing Hotmail via Firefox). Or is it only in the browser during that session (ie. because Hotmail was open and logged in when she went to that site, a script took advantage to send more emails?). Or does it mean the virus has access to her Hotmail account and someone can log-in whenever they want (if she doesn't change the password)? I realize I don't have a good model for how these web-based viruses actually work.

• Answer:

  you've actually detailed two entirely possible ways for such viral code to work. it's impossible to say which one in particular affected your wife given the limited information available, but either one (a script that executes in the browser or a drive-by download that installed when the link was clicked) could have happened and you should probably be treating the machine in question as suspect now.