How be safe from hacker you must be Smart and should have knowledge about tricks used by hacker..
1: Getting hacked by Trojan backdoors or keyloggers.
It is a common way used by hacker to hack you, by giving you a file which you maybe fascinated to open but it surely would be virus but to get save from this attack use online virus scanners(eg. www.virustotal.com/)..if it is a download link then do it so but if it is in a usb or cd then simply scan it with you antivirus but if the hacker is intelligent then he would use Cryptography Trick to hide the files from antivirus...so in this case you need to be smart. ;)
2: Getting hacked by AutoUSB password savers trick..
Well this is a smart way of hacking, in this the hackers useses the Auto play feature to hack the victim simply one of the best brand USB for this attack is Cruiser USB which has a good autoplay feature..to prevent this attack disable the autoplay feature in your windows.
3: If you are totally noob..!
If you are totally noob and the attacker is your friend then simply he would ask you to login through his computer for facebook or yahoo by tricking you saying bla, bla,, bals...and his browser will save your password..
