A quick check on Google identifies a potential candidate for a file named comm.js which relates to cross protocol js based communications which hasn't been updated or patched for the last 3 years and it is possible that someone may be looking for potential sites with it as they may have identified a bug with it that can be exploited.
But basically this is nothing to worry about. It is very common to have any number of 404 errors in your logs either from URL's which once existed and no longer do, typo's in links from other sites to your own, etc. The fact that you don't have such a file on your server means all that is happening is that a relatively inconsiquential amount of bandwidth is being used to return an error message to the client requesting this path and nothing more. If the requests become too frequent and start to concern you with their bandwidth consumption or server load you can discuss with your host blocking the connection at the firewall or do so yourself if you have a firewall you are able to control to block connections from a particular address.