alert http1 $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Request for Image with Specific Byte Range In HTTP Header"; flow:established,to_server; http.method; content:"GET"; http.uri; pcre:"/\x2e(?:png|jpg|jpeg|svg|gif|tiff)$/i"; http.header; content:"Range|3a 20|bytes|3d|"; fast_pattern; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; threshold:type limit,count 1,seconds 300,track by_src; classtype:misc-activity; sid:2072290; rev:1; metadata:affected_product Windows_Client, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_09_28, deployment Perimeter, deployment SSLDecrypt, performance_impact Significant, confidence High, signature_severity Informational, updated_at 2026_09_28, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1105, mitre_technique_name Ingress_Tool_Transfer; target:src_ip;)