alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Kronos Checkin"; flow:established,to_server; http.method; content:"POST"; http.uri; content:".php"; http.header; content:"Content-Length|3a 20|74|0d 0a|"; fast_pattern; http.request_body; pcre:"/^(?P<v1>.).{33}(?P=v1).{9}(?P<v2>.)(?:.{4}(?P=v2)){3}/s"; http.header_names; content:!"Referer|0d 0a|"; content:!"Accept"; content:!"Content-Type"; classtype:command-and-control; sid:2020080; rev:4; metadata:created_at 2014_12_29, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_29;)