alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET HUNTING JAR Sent Claiming To Be Image - Likely Exploit Kit"; flow:established,to_client; flowbits:isset,ET.http.javaclient; http.content_type; content:"image/"; startswith; file.data; content:"PK"; within:2; content:".class"; fast_pattern; distance:10; within:500; classtype:bad-unknown; sid:2018233; rev:4; metadata:created_at 2014_03_08, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_04_24;)