alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Double Extension PIF File Downloaded from Discord (Request)"; flow:established,to_server; http.method; content:"GET"; http.host; content:".discordapp.com"; endswith; fast_pattern; http.uri; content:"/attachments/"; startswith; content:".pif"; nocase; endswith; pcre:"/^\/attachments\/[0-9]{18}\/[0-9]{18}\/\w+\.(?:p(?:ptx?|df|ng)|(?:gi|rt)f|docx?|jpe?g|xlsx?)\.pif$/"; classtype:unknown; sid:2035029; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_02_01, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_02_01, mitre_tactic_id TA0005, mitre_tactic_name Defense_Evasion, mitre_technique_id T1036, mitre_technique_name Masquerading;)