alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Ozone/Darktrack RAT Variant - Server Hello"; flow:established,to_client; flowbits:isset,ET.OzoneRAT; dsize:666; content:"|53 53 48 2d 32 2e 30 2d 64 72 6f 70 62 65 61 72 5f 32 30 31 37 2e 37 35 0d 0a|"; reference:md5,583de02ec747f0316fb7b0e59bd858bd; classtype:trojan-activity; sid:2032543; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_04_08, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_04_08;)