alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET POLICY Serialized Java Payload via RMI Response"; flow:established,to_client; stream_size:client,<,100; flowbits:isset,ET.RMIRequest; content:"|51 ac ed|"; startswith; reference:url,blogs.juniper.net/en-us/threat-research/log4j-vulnerability-attackers-shift-focus-from-ldap-to-rmi; classtype:bad-unknown; sid:2034748; rev:1; metadata:attack_target Client_and_Server, created_at 2021_12_17, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_12_17;)