alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET PHISHING [TW] EvilProxy AiTM Username Checkin"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/?username="; fast_pattern; startswith; pcre:"/^/?username=[a-zA-Z0-9.-]+@[a-zA-Z0-9.]+.[a-zA-Z]{2,3}$/"; http.request_body; content:"|7b 22|visitorId|22 3a 22|"; startswith; content:"|22 2c 22|connect_token|22 3a 22|"; distance:32; within:19; content:"|22 2c 22|connect_hash|22 3a 22|"; distance:36; within:18; classtype:social-engineering; sid:2037849; rev:1; metadata:attack_target Client_Endpoint, created_at 2022_07_29, deployment Perimeter, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_07_29;)