alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cryptojoker Checkin"; flow:to_server,established; http.method; content:"GET"; http.uri; content:".php?info="; fast_pattern; content:"|3a 3a|"; distance:0; http.uri.raw; content:"|4f 4e 4c 25 35 43 6e|"; endswith; http.header_names; content:!"Accept"; content:!"Referer|0d 0a|"; content:!"User-Agent|0d 0a|"; reference:url,www.bleepingcomputer.com/news/security/the-cryptojoker-ransomware-is-nothing-to-laugh-about/; reference:md5,904b0888bfa02d200091fa8ad014d016; reference:md5,bca6c1fa9b9a8bf60eecbd91e08d1323; classtype:command-and-control; sid:2022333; rev:3; metadata:created_at 2016_01_06, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_06_17;)