alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cobalt Strike Malleable C2 (Microsoft Update GET)"; flow:established,to_server; urilen:220; http.method; content:"GET"; http.uri; content:"/c/msdownload/update/others/2016/12/29136388_"; startswith; fast_pattern; content:".cab"; distance:171; endswith; http.user_agent; content:"Windows-Update-Agent/10.0.10011.16384 Client-Protocol/1.40"; bsize:58; http.header_names; content:!"Referer"; reference:url,github.com/rsmudge/Malleable-C2-Profiles/blob/master/normal/microsoftupdate_getonly.profile; classtype:command-and-control; sid:2032752; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_09_18, deployment Perimeter, deployment SSLDecrypt, malware_family Cobalt_Strike, confidence Medium, signature_severity Major, updated_at 2020_11_19, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)