alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Possible TA399/SideWinder Related Empty .rtf Inbound"; flow:established,to_client; http.response_body; bsize:8; content:"|7b 5c|rtf1|20 7d|"; fast_pattern; http.content_len; bsize:1; content:"8"; reference:md5,43d35b5b20f491be219ab2eaa172ec55; classtype:trojan-activity; sid:2055129; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2024_08_08, deployment Perimeter, deployment SSLDecrypt, malware_family Sidewinder, confidence Medium, signature_severity Major, tag TA399, updated_at 2024_08_08;)