The Fenris Rangers was a group of individuals associated with Seven of Nine in the 2390s and 2410s decades. (STO - Legacy mission: "Measure of Morality (Part 2)", PIC episode: "Absolute Candor")
In 2399, Seven of Nine sacrificed her ship to defend the La Sirena against Kar Kentar's bird of prey at Vashti. (PIC episode: "Absolute Candor")
In 2411, Seven investigated potential Borg activity in the Traelus system but became engulfed in an Excalbian trial. (STO - Legacy mission: "Measure of Morality (Part 1)")
Following the trial's conclusion, Seven had determined that the Orion Syndicate had sabotaged the satellites in the Traelus system. Seven informed a Khitomer Alliance officer on Excalbia that she would ask the Fenris Rangers unofficially to dissuade the Syndicate from tampering with the satellites. (STO - Legacy mission: "Measure of Morality (Part 2)")
External link Edit
Fenris Rangers article at Memory Alpha, the wiki for canon Star Trek.