Versions (5)
Version DetailsCurrent
Rev: 3 • Nov 15, 2018, 12:00 PMET MALWARE Observed Malicious SSL Cert (Ursnif Inject Domain)
alert tls $EXTERNAL_NET any -> $HOME_NET any (msg:"ET MALWARE Observed Malicious SSL Cert (Ursnif Inject Domain)"; flow:from_server,established; tls.cert_subject; content:"CN=opzioni.at"; nocase; endswith; tls.cert_issuer; content:"C=US, O=Let's Encrypt, CN=Let's Encrypt Authority X3"; classtype:domain-c2; sid:2026615; rev:3; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_and_Server, created_at 2018_11_15, 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_16, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;)
Nov 15, 2018, 12:00 PM
Sep 16, 2020, 12:00 PM
Sep 21, 2024, 3:00 AM
Sep 25, 2025, 9:34 PM
rules/emerging-malware.rules