alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET USER_AGENTS Suspicious User-Agent (cso)"; flow:established,to_server; http.user_agent; content:"cso v"; startswith; fast_pattern; pcre:"/^[0-9][0-9]?\.[0-9][0-9]?$/R"; reference:md5,5640851c35221c3ae7bbde053d1bb38e; reference:url,app.any.run/tasks/d94c1428-253d-432a-be65-53ea3a0505f4/; classtype:trojan-activity; sid:2030600; rev:1; metadata:attack_target Client_Endpoint, created_at 2020_07_27, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_07_27;)