alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE MSIL/EasyLocker Ransomware CnC Activity"; flow:established,to_server; http.method; content:"GET"; http.uri; pcre:"/\/(?:countdown|check)\/[a-f0-9]{30,45}\/(?:[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})?$/i"; http.host; content:"noobcrypt"; fast_pattern; startswith; http.header_names; content:!"Referer|0d 0a|"; reference:md5,980342a5a783d7f6ce188c575d9ca97a; classtype:command-and-control; sid:2024320; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_05_18, deployment Perimeter, malware_family Ransomware, malware_family EasyLocker, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_08_06, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;)