alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Kronos Checkin M2"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/connect.php?a=1"; fast_pattern; http.header_names; content:!"Referer|0d 0a|"; content:!"Accept"; content:!"Content-Type|0d 0a|"; classtype:command-and-control; sid:2020077; rev:4; metadata:created_at 2014_12_29, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_29;)