Kevin Uxbridge admitted to killing all the Husnock in the third season TNG episode "The Survivors." The Husnock were never seen or heard of again in the TV series. However, there are many Star Trek novels offering further adventures of the Enterprise crew and other Star Trek characters. Assuming Uxbridge only wiped out the Husnock people, their artifacts should still be around to be found eventually. Are remnants of the Husnock civilization ever found in any of the Star Trek novels?
The legacy of the Husnok is explored in the upcoming Star Trek Titan novel Fortune of War by David Mack. From Amazon.com:
Twenty years have passed since the interstellar scourge known as the Husnock were exterminated without warning by a being with godlike abilities. Left behind, intact but abandoned, their desolate worlds and derelict ships brim with destructive potential.
No mentions of real Husnock are in Memory Beta (which covers books etc... in Star Trek franchise). Not an conclusive proof, but Memory Beta is usually pretty thorough.
Husnock was a planet which came under the control of the Terran Empire some time during the mid to late 23rd century.
Under imperial control, the entire planet served as a containment camp for the native and psychotically violent species of the planet who were also known as the Husnock.