Rule History

alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Observed DeerStealer Domain (sonorous-horizon-cfd .cfd) in TLS SNI"; flow:established,to_server; tls.sni; bsize:24; content:"sonorous-horizon-cfd.cfd"; fast_pattern; reference:md5,0e735b887311f0b30c04d15e8da077dd; reference:md5,129d0933e1ab20d42a858424e148d2bc; reference:md5,fe7cad5bc7473c19f26dc3c9da61636d; reference:md5,92f72efd85166433525e8609eff9fa1b; reference:md5,00aa25ec62eb17d1d5f894d9919d887a; classtype:domain-c2; sid:2061578; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2025_04_14, deployment Perimeter, malware_family DeerStealer, performance_impact Low, confidence High, signature_severity Major, updated_at 2025_04_14, mitre_tactic_id TA0037, mitre_tactic_name Command_And_Control, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)