In most cases you must open the attachment, however those sneaky little devils come in all shapes and sizes. I have had them attempt to get me from visiting a website..you browser CAN be your enemy!
I recommend that you practice 'safe pc'. Get a really good virus software and update it regularly.
I uses Nortons Internet Security. Not only does it have a great virus protection, but it also has internet security and alerts you when you are being hacked..and then blocks the hacker.
I get at least 10 intrusions a day!
You never know who wants control of your pc.
Now I know you must be thinking.."I have nothing anyone would want on mine!"..That doesn't matter.
A hacker uses YOUR computer to access other machines of interes..and guess what..when the business or person who has been hacked investigates who 'Hit' them, they find YOU