Suspicious Cisco ASA WebVPN Login Scanning with Spoofed Chrome User-Agent

ATT&CK techniques

Recon → Initial Access

Recon
- T1595.002Vulnerability Scanning
Resource Dev
Initial Access
- T1190Exploit Public-Facing Application
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

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Possible TP-Link Command Injection via WlanNetworkRpm Endpoint (via webserver)

Suspicious Cisco ASA WebVPN Login Scanning with Spoofed Chrome User-Agent

Pivot detection · T1190 · 9 related

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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