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InformationalSplunk security contentNasreddine Bencherchali +2

Cisco Secure Firewall - SSH Connection to Non-Standard Port

This analytic detects inbound SSH connections to non-standard ports on network devices using Cisco Secure Firewall Intrusion Events. APT actors have been observed enabling SSH servers on high, non-default TCP ports…

Description

This analytic detects inbound SSH connections to non-standard ports on network devices using Cisco Secure Firewall Intrusion Events. APT actors have been observed enabling SSH servers on high, non-default TCP ports to maintain encrypted remote access to compromised network infrastructure. This detection leverages Snort signature 65369 to identify SSH protocol traffic on unusual ports, which may indicate persistence mechanisms or backdoor access established by threat actors.

Detection logic

Detection requirements

Platform
ESXiLinuxmacOS

The rule states no platform. This is derived from the ATT&CK technique it maps to.

Log source category
cisco_secure_firewall_threat_defense_intrusion_event

Known benign triggers

  • No false positives have been identified yet.

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