The phrase itself is everyday Russian slang rather than a quote tied to a confirmed film or show, combining durak, meaning fool, with maloletniy, meaning underage or juvenile. As a two-second voice bite it spread through soundboards and short-form edits where a quick, recognisable insult is more useful than a longer rant. Russian-speaking creators keep reusing it because it instantly labels behaviour as immature without needing context, and the short length makes it easy to layer over gameplay, fails and reaction clips.