alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE ArtraDownloader/TeleRAT Checkin"; flow:to_server,established; http.uri; content:".php?a="; content:"&b="; distance:0; content:"&c="; distance:0; content:"Windows|20|"; distance:0; fast_pattern; content:"&d="; distance:0; content:"&e="; distance:0; http.header_names; content:!"User-Agent"; content:!"Referer"; reference:md5,a1bdb1889d960e424920e57366662a59; classtype:command-and-control; sid:2026641; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2018_11_21, deployment Perimeter, malware_family RAT, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_27;)