alert http $HTTP_SERVERS any -> $EXTERNAL_NET any (msg:"ET MALWARE Wordpress Errorcontent CnC Beacon"; flow:to_server,established; http.method; content:"GET"; http.uri; content:"/?ip="; fast_pattern; content:"&referer="; distance:0; content:"&ua="; pcre:"/^\/[a-z]+\/\?ip=/"; http.header_names; content:!"Referer|0d 0a|"; content:!"User-Agent|0d 0a|"; reference:url,isc.sans.edu/diary/Possible+Wordpress+Botnet+C&C:+errorcontent.com/19733; classtype:command-and-control; sid:2021153; rev:4; metadata:affected_product Wordpress, affected_product Wordpress_Plugins, attack_target Client_Endpoint, created_at 2015_05_27, deployment Perimeter, deployment Datacenter, signature_severity Major, tag Wordpress, tag c2, updated_at 2020_10_28, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)