alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET USER_AGENTS Suspicious User-Agent (Presto)"; flow:established,to_server; http.user_agent; content:"Opera/10.60 Presto/2.2.30"; http.header_names; content:!"Accept"; classtype:trojan-activity; sid:2012491; rev:10; metadata:affected_product Any, attack_target Client_Endpoint, created_at 2011_03_12, deployment Perimeter, deprecation_reason Relevance, confidence High, signature_severity Major, tag User_Agent, updated_at 2026_05_07;)