Viruses are on the increase, and whilst there are no 100% secure ways of preventing getting infected there are some things that you can do to stay virus free.
The first step is in playing close attention to links and attachments in emails. Most viruses are spread by people clicking on links and attachments included in emails.
Treating all attachments and links with suspicion is essential. Some of the tell tale signs are displaying the url where the link will take you by hovering over it. Whatever you do, do not click on the link. If the url looks strange, then the chances are the email was a scam and by clicking on the link you could get infected.
Also look at the wording of the email. If it comes from someone you know, but doesnt sound like the type of wording they would normally use, then we recommend calling your contact and see if it was really sent by them or if their account was compromised. Do not reply to the email as the you could be sending the email to the hacker.