I get lots of odd connections to my servers – particularly to my tor relay. Mostly my firewalls bin the rubbish but my web server logs still show all sorts of junk. Occasionally I get interested (or possibly bored) enough to do more than just scan the logs and I follow up the connection traces which look really unusual. I may get around to posting an analysis of all my logs one day.
One of the interesting traces in web logs in the user agent string. Mostly this just shows the client’s browser details (or maybe proxy details) but often I find that the UA string is the signature of a known ‘bot (e.g. Yandex/1.01.001). A good site for keeping tabs on ‘bot signatures is www.botsvsbrowsers.com. But I also find user-agent-string.info useful as a quick reference. If you have never checked before, it can be instructive to learn just how much information you leave about yourself on websites you visit. Just click on “Analyze my UA” (apologies for the spelling, they are probably american) for a full breakdown of your client system.