alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET EXPLOIT_KIT Unknown EK Requesting Payload"; flow:established,to_server; content:".php?ex="; http_uri; content:"&b="; http_uri; content:"&k="; http_uri; pcre:"/&b=[a-f0-9]{7}&k=[a-f0-9]{32}/U"; classtype:exploit-kit; sid:2016896; rev:4; metadata:created_at 2013_05_21, confidence Medium, signature_severity Major, updated_at 2019_07_26;)