alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Cutwail.BE Checkin 2"; flow:established,from_client; dsize:32; content:"|00 00 00 00 FF FF FF FF 3F 57|"; depth:10; content:"|FE FF FF FF FF FF FF FF FF FF FF|"; distance:3; within:11; threshold:type limit, track by_src, seconds 60, count 1; reference:md5,c6d256edcc8879717539f348706061f2; reference:md5,8f17e2a9e7c6cbec772ae56dfffb13cb; classtype:command-and-control; sid:2014272; rev:3; metadata:created_at 2012_02_22, malware_family Win32_Cutwail_BE, confidence Medium, signature_severity Major, updated_at 2019_07_26;)