If it runs fine in Safe Mode but not with a regular boot, you have a software issue. You can get viruses off the internet or via email attachment. They have gotten very sneaky. Look in your downloads folder and question ANYTHING. Most Macs I get in nowadays are infected. Or have things like Genio or MacKeeper.
To verify, reformat the drive, use the "Write Zeros" option to map out any bad blocks. Reinstall the system via a flash drive, external back up drive with a system or via an internet install and see if you problem is gone.
Take it to an ASP and have the logic board tested for this recall.
MacBook Pro Repair Extension Program for Video Issues
Apple has determined that a small percentage of MacBook Pro systems may exhibit distorted video, no video, or unexpected system restarts. These MacBook Pro systems were sold between February 2011 and December 2013.
Apple or an Apple Authorized Service Provider will repair affected MacBook Pro systems, free of charge. See below for details on affected models and service options.
An affected MacBook Pro may display one or more of the following symptoms:
Distorted or scrambled video on the computer screen
No video on the computer screen (or external display) even though the computer is on
Computer restarts unexpectedly
15-inch and 17-inch MacBook Pro models manufactured in 2011
15-inch MacBook Pro with Retina models manufactured from Mid 2012 to Early 2013