alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE PowerShell Downloader CnC Activity"; flow:established,to_server; http.method; content:"POST"; http.user_agent; content:".NET|20|"; content:"E9PQ"; distance:2; within:4; fast_pattern; content:!"|20|"; distance:0; http.header_names; content:!"|0d 0a|Referer|0d 0a|"; classtype:command-and-control; sid:2030151; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_05_11, deployment Perimeter, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_05_11;)