alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (Go/Chaos Botnet)"; flow:established,to_client; tls.cert_subject; content:"C=US, ST=Chaos, O=Chaos, OU=Chaos, CN=127.0.0.1"; bsize:47; fast_pattern; tls.cert_issuer; content:"C=US, ST=Chaos, O=Chaos, OU=Chaos, CN=127.0.0.1"; bsize:47; reference:url,blog.lumen.com/chaos-is-a-go-based-swiss-army-knife-of-malware/; classtype:command-and-control; sid:2039038; rev:1; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_09_29, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_09_29;)