alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/ArtraDownloader CnC Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".php?id="; content:"&&user="; fast_pattern; distance:0; content:"ZxxZ"; distance:0; http.header_names; content:!"User-Agent"; content:!"Referer"; content:!"Accept"; reference:md5,59b043a913014a1f03258c695b9333af; classtype:trojan-activity; sid:2036652; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_04_15, deployment Perimeter, malware_family Win32_ArtraDownloader, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_04_15;)