I'd be very wary about opening any attachments. From experiences (not my own) they tend to have some really nasty viruses activate when you unzip the file. Or some can lay dormant for a period of time and then activate. I have had enough nasty viruses invade my computer to know to not to trust some things like that.

Some particularly nasty ones can watch where you visit, say net banking, and steal your login details and such. Some can take control of your compute remotely from a hacker. I have had to do a full system restore when they hit, and its not a fun task.

On a side note, make sure you back up your system every so often and do a full virus scan and malware scan to keep your computer in check.