The Subytt were a race in the Alpha Quadrant.
In the mid-24th century, the Subytt waged a war with the Kressari in which they developed a type of explosive that was resistant to normal sensor scans. In order to finance their war, the Subytt sold this design to Ferengi weapons traders, who then sold the design throughout the quadrant. The Federation mediated the end of the conflict, but required the means to detect the Subytt explosive in return. In 2371, Je'tran T'ullh and his co-conspirators planned to use a Subytt explosive to kill Damiano governor-elect Ra'ch B'ullhy, but the device was discovered by Starfleet's Lieutenant Commander Worf. (TNG - Perchance to Dream comic: "To Take Arms Against a Sea of Troubles")
In 2370, Quark passed information to Odo that a Subytt freighter crew visiting Deep Space 9 were selling defective isolinear rods to Bajor, allowing Odo to arrest the first officer and two crew members. (DS9 episode: "The Homecoming")
In 2371, a Subytt freighter was delayed upon leaving Deep Space 9 and experienced engine problems when it was eventually able to leave. The Subytt freighter was able to make it back to Deep Space 9 before a plasma storm enveloped the station. (DS9 video game: Harbinger)