alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Criptobit/Mobef Ransomware Checkin"; flow:to_server,established; http.method; content:"GET"; http.uri; content:".php?a="; pcre:"/\.php\?a=\d{5,10}.+\x3a\d\x3a\d\x3a\d\.\d\x3a\d$/"; http.user_agent; content:"Mozilla/5.0 (Windows NT 10.0|3b 20|Win64|3b 20|x64) Edge/13.10586"; fast_pattern; bsize:55; reference:md5,c90a8039f330ba6660a91113f6c53685; classtype:command-and-control; sid:2022845; rev:5; metadata:attack_target Client_Endpoint, created_at 2016_05_31, deployment Perimeter, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_07_14, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;)