alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET USER_AGENTS Si25f_302 User-Agent"; flow:established,to_server; http.user_agent; content:"Si25"; depth:4; classtype:trojan-activity; sid:2012310; rev:7; metadata:created_at 2011_02_14, confidence High, signature_severity Major, updated_at 2020_08_13;)