alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed NimPlant UA (NimPlant)"; flow:established,to_server; http.user_agent; content:"NimPlant C2 Client"; bsize:18; fast_pattern; reference:url,github.com/chvancooten/NimPlant; classtype:trojan-activity; sid:2044339; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_02_24, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_02_24; target:src_ip;)