alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET USER_AGENTS Suspicious User-Agent (Installed OK)"; flow:established,to_server; http.user_agent; content:"Installed OK"; startswith; nocase; reference:md5,16035440878ec6e93d82c2aeea508630; classtype:bad-unknown; sid:2030880; rev:1; metadata:attack_target Client_Endpoint, created_at 2020_09_15, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_15;)