Spies of 24

Mandy
Mandy was a spy working for Ira Gaines. Her mission was to retrieve ID cards from Martin Belkin. In Day 2, she worked for Max, a German ARMS dealer in a plot to assassinate David Palmer. Later on, in Day 4, she worked with terrorist Habib Marwan to launch a nuclear missile. She was granted full immunity in return for information regarding the missile.

Kevin Carroll
Kevin Carroll worked for Ira Gaines and pretended to be Alan York, Janet York's father. He eventually, knowing that Janet had information about Dan Mounts, one of the girls' kidnappers, and killed her.

Nina Myers
Nina Myers pretended to work at CTU during Day 1. She was a good friend of Jack Bauer. On the last episode, Teri Bauer found out that she was a traitor and Nina killed her. Her real name was Yelena.

Lisa Miller
Lisa Miller appeared in Day 6. She was the lover of Vice President Daniels. As it appears, she had been seeing Mark Bishop, and feeding him information about everything in the White House.

Mark Bishop
Mark Bishop had been feeding the information Miller gave him about the circuit board and President Suvarov found out.