: Many searches for this specific filename are intended to find unpatched or misconfigured Internet of Things (IoT) devices, such as older CCTV systems.
You see "403 Forbidden" or "Verification Failed." Fix: This usually occurs in enterprise CMS. Clear your browser cookies and session cache. Re-authenticate to generate a new verification token.
More robustly, use a PHP or Perl wrapper to check a session token before serving the .shtml file. Only include the indexframe.shtml if $_SESSION['verified'] == true .
Based on the terminology used—specifically the combination of view , indexframe , and shtml —you are likely encountering the artifacts of a specific type of or a specific network camera interface .