alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed BlackLotus SSL Certificate Observed"; flow:established,to_client; tls.cert_subject; content:"CN=When They Cry CA"; bsize:19; fast_pattern; reference:url,www.welivesecurity.com/2023/03/01/blacklotus-uefi-bootkit-myth-confirmed/; classtype:trojan-activity; sid:2044418; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_03_01, deployment Perimeter, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_03_01;)