Why isn't my minecraft premium account not working?

I played minecraft for 2 years and i wanted to add a mod pack "ALI-A'S quest " then i wanted to play with my normall minecraft and it said play demo WTF! Please guy's someon help me

Uninstall then reinstall Minecraft, it happened to me a few months ago with a different mod. Hope that works!

Its a trojan virus made by the hacker Ali-A
He hacked you, Bye bye Minecraft.

Guy's thanks for the support i found the solution my minecraft profile got transfered to my other email (i don't even know why ) stupid mojang