alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Possible CastleRAT C Variant Malware Outbound Request To IP Geo Location Service ip-api M2"; flow:established,to_server; urilen:20; http.method; content:"GET"; http.uri; content:"|2f|line|2f 3f|fields|3d|147505"; depth:20; fast_pattern; http.header; content:"Connection|3a 20|Keep-Alive|0d 0a|Host|3a 20|www.ip-api.com|0d 0a 0d 0a|"; depth:48; reference:url,tria.ge/250814-wyqstsyjx3; reference:url,assets.recordedfuture.com/insikt-report-pdfs/2025/cta-2025-1209.pdf; classtype:trojan-activity; sid:2066409; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Mac_OSX, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_12_19, deployment Perimeter, deployment SSLDecrypt, malware_family CastleRAT, performance_impact Moderate, confidence Medium, signature_severity Major, updated_at 2025_12_19, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel; target:dest_ip;)