alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Bisonal Backdoor CnC Activity (POST)"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/post.asp"; endswith; http.host; content:".com#.com"; fast_pattern; endswith; http.header_names; to_lowercase; content:!"|0d 0a|referer|0d 0a|"; reference:md5,60490ea995531924f77af5f1bfb38eec; reference:url,twitter.com/nao_sec/status/1438460553479921665; classtype:trojan-activity; sid:2033964; rev:2; metadata:attack_target Client_Endpoint, created_at 2021_09_16, deployment Perimeter, deployment SSLDecrypt, malware_family Bisonal, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_25, reviewed_at 2023_08_22;)