.php indicates the server is using the PHP scripting language.
If you are a developer, the best way to prevent your site from showing up in these searches—and being targeted—is to Always use prepared statements and keep your CMS (like WordPress) updated to the latest version. inurl php id 1
The reason this specific string is so popular in the hacking community is that it often points to 1 is the value being passed to that parameter
?id= is a GET parameter used to request a specific record from a database (like a product page or a news article). 1 is the value being passed to that parameter. inurl:php
The use of advanced search operators to find security holes is known as or Google Hacking . The Google Hacking Database (GHDB) contains thousands of these strings. inurl:php?id=1 became the "Hello World" of dorking because: Ubiquity: Millions of sites used this exact URL structure. Simplicity: It’s easy to remember and type.
Early hacking tools (like Havij or sqlmap) often used this query as a starting point to find targets for automated exploitation. Is It Still Relevant Today?