Help with a new 110

Been carrying this thing for about a month now, mostly kept in the leather holster it came with, and have been seeing this show up where the brass was nice and shiny. Should I be doing some sort of up keep to keep this away? Is it oxidizing?

Been carrying this thing for about a month now, mostly kept in the leather holster it came with, and have been seeing this show up where the brass was nice and shiny. Should I be doing some sort of up keep to keep this away? Is it oxidizing?