alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Enfal CnC GET"; flow:to_server,established; http.method; content:"GET"; http.uri; content:"docs/"; fast_pattern; pcre:"/^\/(?:tran|http)docs\//"; http.header; pcre:"/^Host\x3a[^\r\n]+\r\n(?:Cache-Control|Pragma)\x3a\x20no-cache\r\n(?:\r\n)?$/mi"; http.header_names; content:!"User-Agent|0d 0a|"; content:!"Referer|0d 0a|"; reference:md5,f1b341d3383b808ecfacfa22dcbe9196; classtype:command-and-control; sid:2021080; rev:5; metadata:created_at 2015_05_09, performance_impact Significant, signature_severity Major, updated_at 2024_03_25;)