Many .shtml files from the early 2000s are vulnerable to SSI injection attacks. Security researchers use this exact string to find outdated servers.
Advanced search strings used by researchers to find specific file types or server configurations.
inurl:view/index.shtml intitle:"index of" "14 better"
When you search for these specific URL patterns, you are often bypassing a website's intended homepage and landing directly on the control panel of a physical device.