Rule History

alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed PhantomNet C2 Domain (associate .freeonlinelearning .com in TLS SNI)"; flow:established,to_server; tls.sni; dotprefix; content:".associate.freeonlinelearning.com"; endswith; fast_pattern; reference:url,news.sophos.com/en-us/2024/06/05/operation-crimson-palace-sophos-threat-hunting-unveils-multiple-clusters-of-chinese-state-sponsored-activity-targeting-southeast-asia/; classtype:trojan-activity; sid:2053337; rev:2; metadata:attack_target Client_Endpoint, created_at 2024_06_07, deployment Perimeter, deprecation_reason Relevance, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_04_21, reviewed_at 2025_04_21, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)