alert icmp $EXTERNAL_NET any -> $HOME_NET any (msg:"GPL ICMP L3retriever Ping"; icode:0; itype:8; content:"ABCDEFGHIJKLMNOPQRSTUVWABCDEFGHI"; depth:32; reference:arachnids,311; classtype:attempted-recon; sid:2100466; rev:5; metadata:created_at 2010_09_23, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)