alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET EXPLOIT_KIT Grandsoft/SofosFO EK PDF URI Struct"; flow:established,to_server; flowbits:set,et.exploitkitlanding; http.uri; content:".pdf"; endswith; fast_pattern; pcre:"/^\/\d{1,2}(?P<l>[A-Z])\d{1,2}(?P=l)\d{1,2}(?P=l)\d{1,2}\.pdf$/"; classtype:exploit-kit; sid:2017699; rev:6; metadata:created_at 2013_11_09, confidence High, signature_severity Major, updated_at 2024_03_17;)