The number of Hotmail email accounts which are being hacked seems to be increasing significantly. If you receive an email from a contact you know, with about a dozen other recipients listed and the only message is a link to a website in the body of the message, be sure not to click on that link.
If you can get in touch with the [apparent] sender by phone, tell them that their Hotmail account (and possibly their computer) has been hacked and their email account password will have been changed to prevent them accessing it.
They should have their computer checked professionally before connecting to the Internet again and phone Hotmail to have their password reset.
The new password should definitely be hard to crack – look for advice on password generation. Checking that virus protection and firewall software is up to date is also advisable.