Cisco Secure Firewall - Snort Rule Triggered Across Multiple Hosts
This analytic identifies Snort intrusion signatures that have been triggered by ten or more distinct internal IP addresses within a one-hour window. It leverages Cisco Secure Firewall Threat Defense logs and focuses…
Description
This analytic identifies Snort intrusion signatures that have been triggered by ten or more distinct internal IP addresses within a one-hour window. It leverages Cisco Secure Firewall Threat Defense logs and focuses on the IntrusionEvent event type to detect activity that may indicate broad targeting or mass exploitation attempts. This behavior is often associated with opportunistic scanning, worm propagation, or automated exploitation of known vulnerabilities across multiple systems. If confirmed malicious, this could represent the early phase of a coordinated attack aiming to gain a foothold on several hosts or move laterally across the environment.
Detection logic
Detection requirements
- Platform
- ESXiLinuxmacOSNetwork DevicesWindows
The rule states no platform. This is derived from the 2 ATT&CK techniques it maps to.
- Log source category
- cisco_secure_firewall_threat_defense_intrusion_event
Known benign triggers
- False positives should be minimal. Simultaneous vulnerability scanning across multiple internal hosts might trigger this, as well as some snort rules that are noisy. Disable those if necessary or increase the threshold.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| www.cisco.com/c/en/us/td/docs/security/firepower/741/api/FQE/secure_firewall_estreamer_fqe_guide_740.pdf | 18 |
From the source
- At source
- Open at source
- Upstream identifier
- a4c76d0a-56b6-44be-814b-939746c4d406
- Tagged by the source as
- Cisco Secure Firewall Threat Defense AnalyticsNetworknetworkSplunk CloudSplunk EnterpriseSplunk Enterprise Securitynetwork
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Aug 26, 2026
- Version
- 1