The second most popular way to hijack a computer would be to have that device visit a malicious website. You might have a local Antivirus product installed on your computer that has ‘Web Protection’ features, however most if the time it is too late. Changing your DNS to a OpenDNS that has blacklisted malicious sites is fast and most of all free.
Are you having trouble trying to send email from MYOB via outlook? This solution should fix the error that you are getting.