Homicide International Trust, appropriately shorthanded to HIT, is a fraternity of assassins employing killers from around the world to carry out "hits" on their various targets: it has been described as a "sort of multinational Murder Incorporated." Its creator and chairman was Nicholas Helman, whose exclusive club in Los Angeles was one of the organization's fronts.
Murdoc was employed by them, and considered one of their best field men. However, a rift developed when he tried to retire following his repeated failures to deal with MacGyver: HIT refused to let him go, instead putting a hit out on him, and eventually holding his sister hostage in an attempt to bring him in. Cornered, Murdoc was forced to ask for help from MacGyver: the two of them successfully infiltrated Helman's private club and rescued Ashton, causing the death of Helman in the process. Following this, Murdoc turned over to MacGyver a tape containing everything he knew about the organization. (Halloween Knights)
Despite this, HIT was not fully taken down: it was still operating a year later, albeit under new management. Murdoc attempted to rejoin their ranks once, and was allowed to do so on the condition that he first eliminate MacGyver, the only stain on his otherwise perfect record. After failing to kill him again, Murdoc was turned away, and forced to look for employment elsewhere: HIT's fate after this is unknown. (Strictly Business)