This sounds like a "rebadged" type lens. Forgive me for questioning, but are you certain it is "Samsung" and not "Samyang"? The reason I ask is if you look at this site you might see something that looks similar: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290756284712#ht_500wt_1288
If so, it would be an older, but not necessarily rare lens. It willl certainly not be in NX mount but find out which mount it is and buy an adapter and have a go with it. These types of lenses tend to be a bit soft wide open, but they can be fun and give interesting results at times. Have fun with it!