alert http $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET MALWARE Ransomware Locky CnC Beacon";
flow:established,to_server;
urilen:11;
http.method;
content:"POST";
http.uri;
content:"/submit.php"; fast_pattern;
http.header;
content:"www-form-urlencoded|0d 0a|";
http.user_agent;
content:"User-Agent|3a|"; startswith;
http.request_body;
pcre:"/[\x80-\xff]/";
http.header_names;
content:!"Referer|0d 0a|";
content:!"Accept";
reference:md5,042b2e41a14b67570a993ef909621954;
classtype:command-and-control;
sid:2022665; rev:5;
metadata:attack_target Client_Endpoint, created_at 2016_03_28, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_06_29, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)