My mom's Hotmail address book has been hacked. What should she do now?

Over the past 3 weeks, apparently, my mom has sent about 4 mass emails to everyone in her email address book at Hotmail. Essentially spam from a company called Ebestcargo.com, this email has either infected her address book or the address book of others, including a Yahoo group. All the emails sent from her have only said her email address in the from line. We changed her passwords on hotmail + facebook…