alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Win32.Nitol.K Variant CnC"; flow:established,to_server; content:"|0b 00 00 00|"; depth:4; content:"Windows|20|"; distance:4; within:8; content:"|00|"; within:5; content:"|7c b4 ab b2 a5 7c|"; fast_pattern; reference:md5,56bff68317a0af08f749a1c717125cf3; classtype:command-and-control; sid:2022337; rev:4; metadata:created_at 2016_01_07, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_12_18;)