The Worm is a secret society and criminal organization that exists inside the United Stars Navy. While it is strictly prohibited for an Officer of the Fleet to be a member of any secret society, fraternity or association (within the fleet) the Union fleet is so huge and old (Having well over a trillion Beings in active duty and existing for 3000 years) the formation of societies happened. There are sanctioned ones that are open and must be approved by Fleet command but there are those who are not.
The Worm is one of the oldest Organizations and was founded by a Commodore and later Admiral of the first hour, to use the enormous resources of the Fleet to personally enrich the members of the Worm. The Worm as a society grew in secret and defied all attempts of CID to be eradicated.
In 5019, Erica Olafson and the Crew of the USS Tigershark managed to capture the “Purple Worm” who was the leader of that organization. It turned out to be the very same Admiral who started the Worm organization and it was discovered that he was one of the Immortals picked by the Guardian.
With the help of Narth and a Brain dump, as well as with NELSON going online and the introduction of 500 Narth Agents into the PSI Corps, Admiral McElligott made the announcement in 5022 that the Union Fleet was 100% free of secret societies and that there were no Agents of the Worm organization within the fleet.
The Worm was indeed expelled and eradicated from within the Fleet, but a few cells remained in the civilian world, but are nothing more than one of many criminal organizations that come and go.