alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE W32/Symmi.46846 CnC Beacon"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/notify.php"; fast_pattern; http.user_agent; content:"Mozilla/4.0 (compatible|3b 20|MyApp)"; startswith; http.header_names; content:!"Referer|0d 0a|"; reference:md5,fe5dc2a4ee8aa084c9da42cd2d1ded2e; classtype:command-and-control; sid:2019948; rev:4; metadata:attack_target Client_Endpoint, created_at 2014_12_16, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_09_28, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)