alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE APT OSX.XSLCmd CnC Beacon"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/compose.aspx?s="; fast_pattern; http.accept_lang; content:"zh-cn"; bsize:5; http.user_agent; content:"Mozilla/4.0 (compatible|3b| MSIE 6.0|3b| Windows NT 5.1)"; reference:url,fireeye.com/blog/technical/malware-research/2014/09/forced-to-adapt-xslcmd-backdoor-now-on-os-x.html; classtype:targeted-activity; sid:2019136; rev:6; metadata:attack_target Client_Endpoint, created_at 2014_09_08, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_05_04, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)