Worm

A worm was a type of self-propagating code that spread throughout computer systems for nefarious reasons. A worm was used during Day 3 to attack CTU Los Angeles.

While working at CTU Los Angeles, double agent Nina Myers installed a computer worm in a part of the computer infrastructure she knew would never be updated. It remained there for 4 years after Nina was arrested, and during Day 3 she tricked Jack Bauer into setting it off. Pretending to be giving him a phone connection to Marcus Alvers, she had Jack type 1775531 into a satellite phone, before telling him to hold 9 for three seconds. Finally, she had him type 95731*6 which triggered the worm in CTU's systems.

The malware copied itself into CTU's kernel, and quickly began to bring down agency connectivity, before starting to damage the CTU firewall and expose their files to the outside world. Chloe O'Brian was released from holding to help counter-act the worm's effects, and she and Adam Kaufman worked together to stop it. Jack had Nina tell Chloe how to slow the worm's progress, which she did, but Nina refused to give the kill code until she was safely delivered to Mexico. However, Chloe managed to stop the worm herself, restoring the CTU systems.