alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET INFO Zip File"; flow:established,from_server; file_data; content:"PK|03 04|"; within:4; flowbits:set,et.http.PK; flowbits:noalert; classtype:misc-activity; sid:2017669; rev:5; metadata:created_at 2013_11_06, confidence High, signature_severity Informational, updated_at 2019_07_26;)