Rule History

alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Cobalt Strike Related Domain (cdnwin .xyz in TLS SNI)"; flow:established,to_server; tls.sni; content:"cdnwin.xyz"; bsize:10; fast_pattern; reference:url,thedfirreport.com/2021/10/18/icedid-to-xinglocker-ransomware-in-24-hours/; classtype:domain-c2; sid:2034304; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_10_29, deployment Perimeter, malware_family Cobalt_Strike, confidence High, signature_severity Major, tag c2, updated_at 2021_10_29, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)