The attacker might:
- not know that the website is running asp, or
- be a robot.
In most cases, I would say it is the latter: many, many crawlers try all sorts of attacks on every website, hoping to find a website where they get lucky. Figuring out, by hand, which technology is used by a website, costs much more time than just doing a few GET requests and matching the expected output.
what will happen when a php code is tried to execute on an asp running web server. whether this will create an impact on the server and any chances of getting compromised
No, there will be no impact at all. If there is no PHP anywhere on the server, then PHP code will never do anything.
Well, it could theoretically be that valid PHP code is also valid ASP code. I don't know ASP that well, but a
function_call() is probably similar in both languages... so any PHP attack will not work, but any attack that is valid for both languages might work, if your website is vulnerable... but the odds of this are negligible. Attacks almost never work in multiple languages, especially not if someone is blindly trying requests against your web server.
This is very common and generally nothing to worry about. It generally impacts common setups like Wordpress, PhpMyAdmin, Typo3, Joomla, etc.