alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE VaultCrypt Checkin"; flow:to_server,established; urilen:6; http.method; content:"GET"; http.uri; content:"/v.vlt"; fast_pattern; http.header; content:"|0d 0a|UA-CPU|3a 20|"; reference:md5,d8bd77eebee2e74ea74679bf3f1f7210; classtype:command-and-control; sid:2021091; rev:4; metadata:created_at 2015_05_13, signature_severity Major, updated_at 2020_10_01;)