alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET PHISHING Successful Generic AES Phish M2 Oct 24 2017"; flow:established,from_server; flowbits:isset,ET.genericphish; http.content_type; content:"text/html"; startswith; file.data; content:"Aes.Ctr.decrypt"; nocase; fast_pattern; pcre:"/^\s*?\(\s*[^,]+,\s*?[^,]+,\s*?(?:128|256|512)\s*?\)/Rsi"; classtype:credential-theft; sid:2024998; rev:4; metadata:affected_product Web_Browsers, attack_target Client_Endpoint, created_at 2017_10_24, deployment Perimeter, confidence Medium, signature_severity Critical, tag Phishing, updated_at 2020_08_17, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1566, mitre_technique_name Phishing;)