Shell program

A shell program is a Spark-manipulating control program from the Beast Wars and Beast Machines portions of the Generation 1 continuity family.

The ultimate shooting game.

A shell program is a Predacon-designed personality altering program that can be installed within a Transformer to change the way they act. A shell program can even compel a Transformer to behave in ways diametrically opposed to what they would do without the shell program.

Fiction

Beast Wars cartoon

Upon the landing of each stasis pod, the Maximals and Predacons would both rush to the scene in hopes of recruiting the protoform inside to their team. The protoforms were Maximals by default, but the Predacons were able to turn some by implanting shell programs before waking the protoform up. Blackarachnia and Inferno joined the Predacons through this scheme. (Rampage and Quickstrike joined without being reprogrammed.) Rhinox's brief stint as a Predacon was not explicitly explained, but may have also been the result of a shell program. Dark Designs

Eventually, despite her shell program, Blackarachnia decided to side with the Maximals. When hidden code in her shell program began to threaten her life, the Maximals attempted to remove it entirely, a procedure which was very dangerous for her. Rhinox then conducted a strange kind of virtual, videogame-style "search and destroy" mission within Blackarachnia to accomplish this. Sadly, a safeguard that Tarantulas included in the program terminated her before Rhinox could finish the removal. (She was then revived "magically" by the Transmetal driver.)

Beast Machines Cartoon

Megatron utilized the sparks of Silverbolt, Waspinator, and Rhinox to power shell programs giving life to the original three Vehicon generals. Obsidian and Strika, however, did not appear to be altered in this manner.

From Teletraan I: The Transformers Wiki, a Wikia wiki.