Cisco SA - Automated Web Reconnaissance via HTTP Access Errors
This analytic detects probable automated web reconnaissance using Cisco Secure Access proxy telemetry. A high volume of HTTP client errors (401/403/404/etc) across many unique URLs in a short window is consistent…
Description
This analytic detects probable automated web reconnaissance using Cisco Secure Access proxy telemetry. A high volume of HTTP client errors (401/403/404/etc) across many unique URLs in a short window is consistent with directory/file enumeration behavior generated by tools such as Gobuster, DirBuster, ffuf, or Burp Intruder. Detecting this pattern helps identify pre-exploitation scanning activity, insider reconnaissance, compromised endpoints performing discovery, and attempts to find hidden administrative paths, APIs, backups, and exposed application files.
Detection logic
Detection requirements
- Platform
- PRE
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- cisco_secure_access_proxy
Known benign triggers
- Aggressive web vulnerability scanners, QA automation, uptime monitoring, and authorized security assessments can generate high HTTP error volumes with large URL diversity. Tune by allow-listing known scanner hosts, user agents, test domains, and approved assessment windows using the filter macro.
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 |
|---|---|
| attack.mitre.org/techniques/T1595/ | 4from 2 sources |
From the source
- At source
- Open at source
- Upstream identifier
- 4cd44520-d404-4ca8-b736-c9d6b86ecf31
- Tagged by the source as
- Cisco Secure Access AnalyticsEndpointnetworkSplunk CloudSplunk EnterpriseSplunk Enterprise Securitythreat
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