alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING jpg download from fileupload .site"; flow:established,to_server; http.method; content:"GET"; http.uri; content:".jpg"; endswith; http.host; content:"fileupload.site"; bsize:15; fast_pattern; http.header_names; content:!"Referer"; classtype:bad-unknown; sid:2033287; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_07_09, deployment Perimeter, performance_impact Low, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_07_09;)