alert dns any any -> any any (msg:"ET CURRENT_EVENTS [Fireeye] Backdoor.DNS.BEACON.[CSBundle DNS]"; content:"|00 01 00 01|"; offset:4; depth:4; content:"|03|"; within:15; content:"|0a|_domainkey"; distance:3; within:11; content:"|00 00 10 00 01 c0 0c 00 10 00 01 00 00 00 02 01 00 ff|v=DKIM1\; p="; fast_pattern; reference:url,github.com/fireeye/red_team_tool_countermeasures; classtype:trojan-activity; sid:2031265; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_12_08, deployment Perimeter, confidence High, signature_severity Major, tag c2, updated_at 2020_12_09, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)