alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Win32/Valak <v20 Checkin - Server Response"; flow:established,to_client; http.stat_code; content:"200"; http.response_body; content:"|2d 2d|BODYdmFyIGNvbmZpZyA9IHsNCiA"; startswith; reference:md5,c254b4f261a6f426c282ed8858a7bee0; reference:url,medium.com/@prsecurity_/casual-analysis-of-valak-c2-3497fdb79bf7; classtype:command-and-control; sid:2029194; rev:1; metadata:attack_target Client_Endpoint, created_at 2019_12_22, deployment Perimeter, malware_family Win32_Valak, performance_impact Low, confidence High, signature_severity Major, updated_at 2019_12_22;)