Agents of STRIKE
The Hand is a criminal organization and a secret society that, according to its members, is ancient and dates back to the Sengoku period of Japan (in the 15th century).
They claim to be ninjas. While they absolutely adopt the dress, weaponry, and fighting techniques commonly associated with ninjas, it is unclear if there is any authenticity to their claims or practices.
Regardless of how authentic they are, the Hand are very dangerous and are responsible for assassinations, sabotage, industrial espionage, and terrorist attacks.
It is difficult to get reliable intel on the Hand, due to their members tendency to commit suicide when apprehended.