alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Vawtrak/NeverQuest Server Response"; flow:established,from_server; content:"|0d 0a 0d 0a|ok"; fast_pattern; file_data; content:"ok"; within:2; byte_test:1,<,0x1b,0,relative; content:"|00|"; distance:1; within:1; flowbits:isset,ET.Vawtrak; classtype:trojan-activity; sid:2019499; rev:5; metadata:created_at 2014_10_24, signature_severity Major, updated_at 2019_10_08;)