A User Agent that says just "Mozilla/4.0" is a bot, right?

Question

I'm getting several requests in web apps that are basically wrong in ways my code shouldn't be generating... Mainly it's requests to .ashx without any GET parameters specified.

The user agent is "Mozilla/4.0" (nothing more than that) The IPs vary from day to day.

This is a bot, right?

Thanks!

Answer 1

Sorry to bump old question, but I think this is the bot used by the Great Firewall of China. They crawl web contents, and do their censorship.

Check your log and see if there is anything like 'GET /cert/bazs.cert'.

100% sure if this is found.

Answer 2

This seems very odd to me. Any legitimate bot would identify itself in a way you can recognize. Any malicious bot would be able to do a much better job making the user agent look like a normal browser. This is somewhere in the middle. That, combined with the bad requests, leads me to believe you're dealing with plain old incompetence.

Either way, you probably want to 404 these requests rather than return a yellow screen error.

Answer 3

According to http://www.user-agents.org the 'Yahoo Mindset: Intent-driven Search' bot reports this.

But yeah it wouldn't be a browser reporting that.