Suspicious Cisco ASA WebVPN Login Scanning with Spoofed Chrome User-Agent
- Category
- webserver
- Author
- HuntRule
- Published
- 2026-08-28
- Updated
- 2026-08-28
ATT&CK techniques
Recon → Initial AccessResource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects inbound requests to Cisco ASA web login endpoints /+CSCOE+/logon.html and /+webvpn+/index.html that carry the single spoofed browser identifier Chrome/102.0.5005.63 used across a coordinated scanning botnet. The activity mapped a surge of 25,000 IPs probing Cisco ASA devices, frequently a precursor to a newly disclosed vulnerability being weaponized for initial access.
Reporting behind it
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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