alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET EXPLOIT_KIT CVE-2013-2423 IVKM PoC Seen in Unknown EK"; flow:to_client,established; content:"Union1.class"; content:"Union2.class"; fast_pattern; content:"SystemClass.class"; content:"PoC.class"; flowbits:isset,ET.http.javaclient; reference:url,weblog.ikvm.net/CommentView.aspx?guid=acd2dd6d-1028-4996-95df-efa42ac237f0; classtype:exploit-kit; sid:2016831; rev:3; metadata:created_at 2013_05_07, confidence Medium, signature_severity Major, tag CISA_KEV, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)