alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET HUNTING HTTP Redirect to Dropbox Hosted PDF"; flow:established,to_client; http.stat_code; content:"302"; http.location; content:"https://www.dropbox.com"; startswith; fast_pattern; content:".pdf"; nocase; classtype:misc-activity; sid:2071821; rev:1; metadata:affected_product Web_Browsers, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_08_27, deployment Perimeter, deployment SSLDecrypt, performance_impact Moderate, confidence High, signature_severity Informational, updated_at 2026_08_27, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)