alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE W32/Karagany.Downloader CnC Beacon"; flow:established,to_server; urilen:6; content:".htm"; http_uri; content:"Mozilla/5.0 (compatible|3B| MSIE 9.0|3B| Windows NT 6.0|3B| Trident/5.0)"; fast_pattern; http_user_agent; pcre:"/^\x2F[a-z]{1}\x2Ehtm$/U"; threshold:type limit, track by_src, seconds 60, count 1; reference:url,malwaremustdie.blogspot.co.uk/2013/01/once-upon-time-with-cool-exploit-kit.html; reference:url,www.fortiguard.com/latest/av/4057936; reference:md5,92899c20da4d9db5627af89998aadc58; classtype:command-and-control; sid:2016211; rev:6; metadata:attack_target Client_Endpoint, created_at 2013_01_15, deployment Perimeter, signature_severity Major, tag c2, updated_at 2022_03_17, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)