alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Operation Buhtrap CnC Beacon 2"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/menu.php"; fast_pattern; endswith; http.user_agent; content:"rv|3a|20.0"; content:"Firefox/20.0"; distance:0; http.request_body; pcre:"/^[\x20-\x7e\r\n]{0,20}[^\x20-\x7e\r\n]/"; http.content_type; content:"application/octet-stream"; bsize:24; http.header_names; content:!"Referer|0d 0a|"; reference:url,welivesecurity.com/2015/04/09/operation-buhtrap/; reference:md5,24fac66b3a6d55a83e1309bc530b032e; classtype:command-and-control; sid:2020891; rev:6; metadata:attack_target Client_Endpoint, created_at 2015_04_11, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_10_05, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)