alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE SocGholish Domain in TLS SNI (books .friendsofthefolsomlibrary .org)"; flow:established,to_server; tls.sni; bsize:35; content:"books.friendsofthefolsomlibrary.org"; fast_pattern; reference:url,community.emergingthreats.net/t/et-socgholish-rules-response-guidance/335; classtype:domain-c2; sid:2054706; rev:5; metadata:attack_target Client_Endpoint, tls_state TLSEncrypt, created_at 2024_07_26, deployment Perimeter, malware_family SocGholish, performance_impact Low, confidence High, signature_severity Critical, tag compromised_website, updated_at 2026_06_08, reviewed_at 2025_08_05, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1189, mitre_technique_name Drive_by_Compromise; target:src_ip;)