An average-everyday guy with a crappy life wins the $42 million lottery. But what he doesn’t know is that the system is corrupt and they now want him dead.

You say a corrupt system wants him dead; however a system is faceless, you need a main antagonist to put a face on that corrupt system.
-----
"After winning a record breaking lottery an average Joe's life is endangered when a corrupt lottery official targets him for Death."
-----
Alright mine still needs work but I hope you see what I did. I started with the event that triggers the story then added an antagonist.

Hope that helped, good luck with this!