Detection catalogue

Explore published rules with transparent provenance, licensing, and ATT&CK mappings.

detections

Loading detections…

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 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.

ATT&CK coverage

Outside the enterprise matrix

T1021.004

Detection requirements

Log source category: cisco_secure_firewall_threat_defense_intrusion_event

What the source says

What fires this without an attack behind it

No false positives have been identified yet.

References

https://www.cisa.gov/news-events/cybersecurity-advisories/aa25-239a

Tagged by the source as

Cisco Secure Firewall Threat Defense AnalyticsSalt TyphoonNetworknetworkSplunk CloudSplunk EnterpriseSplunk Enterprise Securitynetwork

Detection logic

Published to signed-in readers

The query as its source wrote it, its canonical form, and the content hash that pins this exact revision.