Versions (4)
Version DetailsCurrent
Rev: 3 • Jun 27, 2019, 12:00 PMET MALWARE Observed Malicious SSL Cert (Ursnif CnC)
alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (Ursnif CnC)"; flow:from_server,established; tls.cert_subject; content:"CN=tupeska.top"; nocase; fast_pattern; endswith; tls.cert_issuer; content:"C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3"; classtype:domain-c2; sid:2027620; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2019_06_27, deployment Perimeter, malware_family ursnif, performance_impact Low, confidence High, signature_severity Major, tag SSL_Malicious_Cert, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_17, mitre_tactic_id TA0042, mitre_tactic_name Resource_Development, mitre_technique_id T1587, mitre_technique_name Develop_Capabilities;)
Jun 27, 2019, 12:00 PM
Sep 17, 2020, 12:00 PM
Sep 21, 2024, 3:00 AM
Sep 23, 2025, 9:34 PM
rules/emerging-malware.rules