It is rare to come across cheaters in Dota 2, but they do exist and are a pain for anyone looking forth to play the game. Valve is constantly on top of this and issues permanent bans frequently to keep the game clean and free from scripters. The scripters usually employ scripts which help them permanently hex their opponent which gives them an undue advantage in the game.
We have issued another wave of permanent matchmaking bans to players who were abusing cheats (e.g. auto-hex scripting).
— DOTA 2 (@DOTA2) June 20, 2018