alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET USER_AGENTS Suspicious User-Agent (HTTP Downloader)"; flow:established,to_server; threshold:type limit, count 2, track by_src, seconds 300; http.user_agent; content:"HTTP Downloader"; depth:15; classtype:trojan-activity; sid:2008428; rev:12; metadata:affected_product Any, attack_target Client_Endpoint, created_at 2010_07_30, deployment Perimeter, confidence High, signature_severity Major, tag User_Agent, updated_at 2020_10_16;)