From Hattrick

Evil in Hattrick is used more in a jocular manner than anything else. These things are considered by many to be "evil" for various reasons, ranging from a strong advantage in a match that doesn't echo people's opinion of how football is really played (see WTM) to a simple scapegoat (see the Form Monkey), to events that seem to happen out of the blue (see injury), to a team that has dominated a country for so long that they earn the nickname of evil.