alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/ProPoS CnC Beacon"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; endswith; http.user_agent; content:"Pro PoS"; fast_pattern; startswith; http.accept; content:"application/octet-stream"; bsize:24; http.header_names; content:!"Referer|0d 0a|"; reference:url,blog.talosintel.com/2015/12/pro-pos.html; classtype:command-and-control; sid:2022282; rev:4; metadata:attack_target Client_Endpoint, created_at 2015_12_18, deployment Perimeter, malware_family Win32_ProPoS, 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;)