Complex sentence: The first demonstrated DDos attack was introduced by well known hacker Khan C. Smith during a 1998 illegal Defcon event and later exposed for its use Botnet mechanisms during a lawsuit filed by Earthlink which claims has caused billions in economic damages.
Split into simpler sentences: The first demonstrated DDos attack was introduced by well known hacker Khan C. Smith during an illegal 1998 Defcon event. This DDos attack was later exposed for its use of Botnet mechanisms during a lawsuit filed by Earthlink, which claimed the attack caused billions in economic damages.