alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32/Farfli.CUY KeepAlive M2"; flow:established,to_server; content:"|68 78 20 cf 01 00 00 c0 01 00 00 01 00 00 00 cb|"; startswith; fast_pattern; stream_size:client,>,200; reference:md5,87100cb600d876bd022a4d93ce6305a0; classtype:command-and-control; sid:2035880; rev:2; metadata:created_at 2022_04_08, malware_family Win32_Farfli_CUY, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_04_08;)