alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cryptolocker Checkin"; flow:established,to_server; urilen:11; http.method; content:"POST"; http.uri; content:"/random.php"; fast_pattern; http.user_agent; content:"Mozilla/5."; pcre:"/^\d{2,7}$/R"; http.header_names; content:!"Accept|0d 0a|"; content:!"Referer|0d 0a|"; reference:md5,01be3fc3243d582d9f93d01401c4f95e; classtype:command-and-control; sid:2019353; rev:7; metadata:created_at 2014_10_03, deprecation_reason Relevance, signature_severity Major, updated_at 2024_03_21, reviewed_at 2024_03_21;)