alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Specter Insight Beacon CnC Checkin M3"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/static/resources/|3f|build|3d|"; startswith; pcre:"/^[a-f0-9]{32}/R"; content:"|26|kind|3d|win_an"; fast_pattern; endswith; reference:md5,0f1bab742523821d833701f82a328c2b; reference:url,practicalsecurityanalytics.com/specterinsight/; classtype:trojan-activity; sid:2061552; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_04_14, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag C2_Framework, updated_at 2025_04_14, mitre_tactic_id TA0037, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel; target:src_ip;)