alert http $HOME_NET any -> $EXTERNAL_NET 81:65535 (msg:"ET MALWARE Downloader.Win32.Small CnC Beacon"; flow:established,to_server; http.method; content:"GET"; nocase; http.user_agent; content:"MSDN SurfBear"; depth:13; endswith; classtype:command-and-control; sid:2011269; rev:8; metadata:attack_target Client_Endpoint, created_at 2010_07_30, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_10_13, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)