alert http $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET MALWARE Mermaid Ransomware Variant CnC Activity M2";
flow:established,to_server;
urilen:>50;
http.method;
content:"GET";
http.uri;
content:"data.php?info="; fast_pattern;
pcre:"/^[A-Za-z0-9\?=]{25,}$/Rsi";
http.user_agent;
content:"Mozilla/3.0 (compatible|3b 20|Indy Library)"; bsize:38;
http.header_names;
content:!"Referer";
reference:md5,b3bc3fe63fad42ae8bcd448b8aec3e3e;
classtype:command-and-control;
sid:2029320; rev:1;
metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_01_24, deployment Perimeter, malware_family Ransomware, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_01_24, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;
)