alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Gamaredon APT TryCloudFlare CnC Activity - Known Delimiter in User-Agent"; flow:established,to_server; http.method; content:"GET"; http.host; content:".trycloudflare.com"; endswith; http.user_agent; content:"|3a 3a 2f|"; fast_pattern; reference:url,harfanglab.io/insidethelab/gamaredons-pterolnk-analysis/; reference:url,community.emergingthreats.net/t/sig-et-malware-gamaredon-trycloudflare-activity-known-delimiter-in-user-agent/2758; classtype:command-and-control; sid:2062541; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2025_05_22, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Critical, tag Gamaredon, tag c2, updated_at 2025_05_22, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol; target:src_ip;)