alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE WEBC2-ADSPACE Server Response"; flow:established,from_server; file_data; content:"<!---HEADER ADSPACE style=|22|"; content:"|5c|text $-->"; distance:0; reference:url,www.mandiant.com/apt1; classtype:command-and-control; sid:2016448; rev:2; metadata:created_at 2013_02_20, signature_severity Major, updated_at 2019_07_26;)