alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET EXPLOIT_KIT Unknown_gmf EK - pdfx.html"; flow:established,to_server; http.uri; content:"/pdfx.html"; classtype:exploit-kit; sid:2016055; rev:4; metadata:created_at 2012_12_18, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_23;)