alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cobalt Strike Beacon Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/nova_assets/Sys/_Getcode/keywords="; fast_pattern; startswith; http.cookie; content:"skin="; startswith; content:"sparrow_init="; distance:0; pcre:"/^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})/R"; content:"cfruid="; distance:0; reference:url,twitter.com/mojoesec/status/1403072399860506638; reference:md5,4ba24c8dd87c35c1d7492eb31a14c2bd; classtype:trojan-activity; sid:2033384; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_07_22, deployment Perimeter, malware_family Cobalt_Strike, confidence Medium, signature_severity Major, updated_at 2021_07_22, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)