alert http $EXTERNAL_NET any -> $HOME_NET any (
msg:"ET HUNTING Byte-order mark UTF-EBCDIC";
flow:established,to_client;
flowbits:set,ET.BOM.utfebcdic;
flowbits:noalert;
http.response_body;
content:"|dd 73 66 73|"; startswith;
reference:url,learn.microsoft.com/en-us/windows/win32/intl/using-byte-order-marks;
reference:url,isc.sans.edu/diary/31204;
classtype:misc-activity;
sid:2055651; rev:1;
metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, affected_product Windows_11, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2024_08_30, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Informational, updated_at 2024_08_30;
target:dest_ip;
)