alert http $HOME_NET any -> $EXTERNAL_NET 80 (msg:"🐾 - 🚨 FormBook Infostealer establishing connection to C2"; flow:to_server, stateless; http.method; content:"GET"; http.uri; pcre:"/[\/\/]{1}[a-z0-9]{4}[\/\/]{1}[\?\/]{1}[a-zA-Z0-9]{2,10}[\=\/]{1}[a-zA-z0-9\+\/\_\/\=\/\&\/\-\/]{5,150}[\/\/][a-zA-z0-9\+\/\_\/\=\/\&\/\-\/]{10,}$/"; reference:url,https://malpedia.caad.fkie.fraunhofer.de/details/win.formbook; target:src_ip; metadata:attack_target Client_Endpoint, signature_severity Major, affected_product Windows_XP_Vista_7_8_10_11, mitre_tactic_id TA0011, mitre_tactic_name Command_and_Control, mitre_technique_id T1071.001, mitre_technique_name Application_Layer_Protocol_Web_Protocols, former_category MALWARE, malware_family Formbook, created_at 2024_07_12, updated_at 2024_07_14; sid:3321290; rev:6; classtype:command-and-control;)