alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE WEBC2-CLOVER Checkin APT1 Related"; flow:established,to_server; http.uri; content:"/Default.asp"; http.header; content:"Accept: image/gif,image/x-xbitmap"; content:"|20|MSIE|20|"; http.cookie; content:"PREF=86845632017245"; fast_pattern; reference:url,www.mandiant.com/apt1; reference:md5,29c691978af80dc23c4df96b5f6076bb; classtype:targeted-activity; sid:2016452; rev:4; metadata:created_at 2013_02_22, signature_severity Major, updated_at 2020_10_28;)