Troj/Sdbot-MM is a backdoor Trojan which allows a remote attacker to control the infected computer through IRC channels.
W32/Apribot-C is an IRC backdoor with spreading capability.
Each time the worm is run it tries to connect to a remote IRC server and join a specific channel. The backdoor component then runs in the background as a server process, listening for commands to execute. The infected computer can be used to perform several functions: