alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL/TLS Certificate (QakBot)"; flow:established,to_client; tls.cert_subject; content:"C=GB, ST=Greater Manchester, L=Salfordc, O=Sectigo Limited, CN=Sectigo RSA Domain Validation Secure Server (CA)"; bsize:111; fast_pattern; reference:url,github.com/pan-unit42/tweets/blob/master/2022-10-10-IOCs-for-Cobalt-Strike-from-Qakbot-infection.txt; classtype:domain-c2; sid:2039170; rev:2; metadata:attack_target Client_Endpoint, created_at 2022_10_11, deployment Perimeter, deprecation_reason Age, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_12_02, reviewed_at 2024_12_02;)