alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cobalt Strike Malleable C2 (Meterpreter)"; flow:established,to_server; http.uri; pcre:"/^\/ucD[A-Za-z0-9_\/\-+]{171}$/"; http.request_line; content:"GET|20|/ucD"; fast_pattern; content:"|20|HTTP/1.1"; distance:171; within:9; http.header_names; content:!"Referer"; reference:url,github.com/rsmudge/Malleable-C2-Profiles/blob/master/APT/meterpreter.profile; classtype:command-and-control; sid:2029742; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_03_26, deployment Perimeter, malware_family Cobalt_Strike, malware_family Cobalt_Strike, confidence Medium, signature_severity Major, updated_at 2020_11_10, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)