alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE APT29 Cache_DLL SSL Cert"; flow:established,to_client; tls.cert_subject; content:"CN=private.directinvesting.com"; fast_pattern; reference:md5,8f154d23ac2071d7f179959aaba37ad5; reference:url,www.us-cert.gov/security-publications/GRIZZLY-STEPPE-Russian-Malicious-Cyber-Activity; classtype:targeted-activity; sid:2023931; rev:4; metadata:created_at 2017_02_16, deprecation_reason Age, malware_family APT29_Cache_DLL, confidence High, signature_severity Major, updated_at 2024_04_03, reviewed_at 2024_04_03;)