alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed Karen Ransomware Domain (karen .h07 .wlh .io in TLS SNI)"; flow:established,to_server; tls.sni; content:"karen.h07.wlh.io"; bsize:16; fast_pattern; reference:url,twitter.com/fbgwls245/status/1427610307283677186; reference:url,F155EC35D67F746593CE8CC4E64D33E5; classtype:trojan-activity; sid:2033774; rev:2; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_08_23, deployment Perimeter, deprecation_reason Relevance, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_06_26, reviewed_at 2024_06_26, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)