alert http $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET MALWARE ACR/Amatera Stealer CnC Exfil (POST) M2";
flow:established,to_server;
urilen:3;
http.method;
content:"POST";
http.uri;
content:"/Up"; startswith;
http.connection;
content:"close";
http.content_type;
content:"application/octet-stream";
http.header_names;
content:!"|0d 0a|referer|0d 0a|"; nocase;
http.request_body;
content:"|50 4b 03 04|"; startswith;
content:"|22 2c 22|bt|22 3a 22|SHELLS|22 2c|"; fast_pattern;
reference:md5,ed928383f02f205f92daf0b2d91c78de;
classtype:command-and-control;
sid:2062511; rev:1;
metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state plaintext, created_at 2025_05_21, deployment Perimeter, malware_family Amatera, confidence High, signature_severity Critical, tag c2, updated_at 2025_05_21, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;
target:src_ip;
)