alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cobalt Strike Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/field-keywords/"; endswith; fast_pattern; http.cookie; content:"PREF=ID="; startswith; pcre:"/^[A-Za-z0-9]{262}$/R"; http.header_names; content:!"Referer"; reference:md5,52c5b5e9a2ec443769dba5f44c83d7de; reference:url,cert.gov.ua/article/703548; reference:url,twitter.com/h2jazi/status/1546501374350868481; classtype:trojan-activity; sid:2037735; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_07_11, deployment Perimeter, malware_family Cobalt_Strike, malware_family TA471, malware_family UNC2589, confidence Medium, signature_severity Major, updated_at 2022_07_11, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)