alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Backdoor.Win32.Svlk Client Ping"; flow:from_client,established; dsize:7; content:"|33 0D FF 0A C5 F8 C1|"; depth:7; reference:md5,c929e8c75901c7e50685df0445a38bd0; classtype:trojan-activity; sid:2013893; rev:2; metadata:created_at 2011_11_09, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)