Trying to access browserconfig.xml could be some kind of attack?

Question

Here in the company where I work, we put in a certain system, made in Laravel 4, a system of sending emails every time some kind of error occurs in requests.

We started to distrust some activities, which I will list below, because some come from IPS that are not here in Brazil, besides having some urls in requests that really do not make any sense.

Here are some of them (I replaced our url with the word url):

url/browserconfig.xml //Esse foi campeão de erros, com 19
url/js/===n
url/js/],_default:x.support.htmlSerialize 
url/js/,data:n}).done(function(e){o=arguments,s.html(i?x(=
url/js/).enctype,t.html5Clone=
url/js/!=typeof

All these requests are returning error 404.

The most intriguing is this apparent attempt to exploit javascript, or something like that, because the IP comes from Italy - 93.34.104.108.

Does anyone know what this is about?

Are just errors that can be generated in some browsers, or are attempts to find vulnerabilities?