|An international assassination group who employ professional killers from around the world to carry out contracted assassinations. The organization was initially run by a group of 5 unnamed people known as
"The Board" and headed by Nicholas Helman as the Chairman of the Board. He used his exclusive Helman Club as the base of operations, which included a secret testing facility accessed via a secret door in the clubs billiard room and known as
"Death Row", where potential hit-men where tested to see if they met the criteria of being a HIT assassin. As well as contracting assassinations, HIT was also known to be involved in an arms smuggling operation.
When Murdoc refused his last contract from HIT, the board ordered Nicholas Helman to
"retire" Murdoc. He planned to do this by using Murdoc's sister as bait, but Murdoc enrolled MacGyver's help to save her and when Nicholas failed to kill Murdoc and MacGyver, his right hand person, Sonia Chapel, killed Helman in line with HIT's policy of Zero Tolerance for Failure and assumed the role of Chairman of the Board.
Although Murdoc had given MacGyver enough evidence to close HIT down for good, the organization was somehow able to reform with a new Board of only 3 members and even allowed Murdoc to resume his employment with them, on the condition that he remove the one blemish from his record, MacGyver.
Note of speculation:
In both the Deathlock and Silent World episodes we see the villains taking orders from an un-named group of 3 people which closely resembles HIT. There is no clear indication whether this un-named group is HIT, but it does seem quite reasonable that because they employed killers and a thief to steal a missile for their arms operations, that it could well have been at least the pre-cursor to what would become HIT. You can read more about and discuss this further here.