What's with the weird script in the element inspector?

Question

HTML

In the element inspector on almost every site it is found in such a script <script src="https://aferon.com/"></script>, tell me what it could be

Answer 1

The problem was solved by typing, the element and the function were generated when loading the extension in chrome

Answer 2

var main = { 
   updatePlugin: function() { 
      var dataTimeBlock = document.createElement('div'); 
      dataTimeBlock.innerHTML = new Date(); 
   }, 
   state: {}, 
   setState: function(object) { 
      this.state = this.merge(object, this.state); 
   }, 
   merge: function(destination, source) { 
      for (var property in source) 
      { 
         if (source.hasOwnProperty(property)) { 
            destination[property] = source[property]; 
         }
      }
   return destination; } 
}; 
main.updatePlugin();

Answer 3

Virus. Look for viruses in files