alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET PHISHING Successful NHS Webmail Phish 2020-03-23"; flow:established,to_server; http.method; content:"POST"; http.header; content:"nhs"; nocase; http.request_body; content:"usr="; nocase; content:"&pss="; nocase; fast_pattern; content:"formimage1.x="; nocase; content:"formimage1.y="; nocase; classtype:credential-theft; sid:2029701; rev:2; metadata:affected_product Web_Browsers, attack_target Client_Endpoint, created_at 2020_03_23, deployment Perimeter, confidence Medium, signature_severity Critical, tag Phishing, updated_at 2020_03_23, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1566, mitre_technique_name Phishing;)