alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Cobalt Strike Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/users/"; startswith; content:"/endpoints/events/poll"; endswith; http.referer; content:"https://teams.microsoft.com/_"; bsize:29; http.accept; content:"json"; bsize:4; http.header; content:"|0d 0a|Authentication|3a 20|skypetoken=eyJhbGciOi"; fast_pattern; content:"|0d 0a|x-ms-session-id|3a 20|f73c3186-057a-d996-3b63-"; reference:md5,2daf4f1dbdc4a3d9726f9b447225113a; reference:url,tarlogic.com/blog/hidding-cobalt-strike-traffic; classtype:trojan-activity; sid:2036824; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_06_02, deployment Perimeter, deprecation_reason Age, malware_family Cobalt_Strike, confidence Medium, signature_severity Major, updated_at 2024_12_02, reviewed_at 2024_12_02, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1001, mitre_technique_name Data_Obfuscation;)