alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE x0Proto Ping"; flow:established,from_server; flowbits:isset,et.x0proto; dsize:7; content:"x53|0c|1|0c|0"; depth:7; classtype:trojan-activity; sid:2012239; rev:2; metadata:created_at 2011_01_27, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)