From だだ (dada-) + 漏(も)れ (more, “連(れん)用(よう)形(けい) (ren'yōkei, “stem or continuative form”) of the verb 漏(も)れる (moreru).”).
だだもれ or ダダもれ • (dadamore) ←だだもれ (dadamore)?