This badge has been removed.
The Hero Badge is the hardest to earn out of the 3 first badges (Bandit, Survivor, Hero). You will need to kill 3 bandits , and survive for 3 days. Once you get an Aggresive Kill (From a non bandit), your Hero run will be over. Obtaining the Hero Badge, will give you a blue headband. You cannot get the headband or the badge anymore due to an update Gusmanak made to the game.