alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE W32.DarkVNC Variant Checkin"; flow:established,to_server; stream_size:server,<,5; content:"|4a 01 4f 97 00 1c 84 df cd 3f 1f eb 14 28 b1 ba fa 0e 7e de 22 e0 33 cb a5 8c 23 75 ea e4 e4 3e|"; startswith; fast_pattern; reference:md5,1e081d3f09f24a81194327628a25c214; reference:url,www.malware-traffic-analysis.net/2021/11/05/index.html; classtype:command-and-control; sid:2034557; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_11_30, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_11_30;)