alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE NetWire Variant - Client Hello"; flow:established,to_server; flowbits:set,ET.NetWire; flowbits:noalert; content:"|01 00 00 00 00|"; depth:5; dsize:6; reference:url,researchcenter.paloaltonetworks.com/2014/08/new-release-decrypting-netwire-c2-traffic; reference:url,www.circl.lu/pub/tr-23; classtype:trojan-activity; sid:2021976; rev:2; metadata:created_at 2015_10_20, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)