Cloudflare conundrum - active on a site that doesn't use it?

[Sgt_Kickaxe]

I have a small community hobby forum that I keep udated and regularly check in different browsers, just typical webmaster stuff. 2 days ago a few members began grumbling of having to use a different browser to access the site because Cloudflare was keeping them in an infinite captcha loop. I found that odd since the site doesn't use Cloudflare but I also couldn't replicate the issue on my end... until tonight.

Sure enough I head to my own site with IE and my own site won't let me access it until I complete a microsoft captcha of images with rivers. Completing the captcha just launches another. This behavior is in IE only, it hasn't happened with Chrome or Firefox.

I checked with my host who was also perplexed and did what he could to confirm that the site isn't connected to Cloudflare, he suggested contact my Internet Service Provider since the problem could be local to my area... but before I do.

Has anyone seen this before? We're all scanning for a virus and finding none. The captcha being a microsoft captcha on a cloudflare page but only in IE suggests it's an IE issue but for a couple dozen people all at once to the same site that doesn't even use Cloudflare? it's all a bit odd,

edit: I haven't contacted Cloudflare yet as it takes time when you don't have an account, and it doesn't really matter what they say since they have nothing, or rather should have nothing, to do with the site. If you've seen this before, what was going on?

The site is antique restoration related, nothing nefarious. This is puzzling.

[Kendo]

I recently setup a VPS just for testing stuff and initially I was hitting what you described. I use Firefox Dev and even though it is updated, I sometimes get hung on pages displaying a message about Cloudfare checking my browser and never getting anywhere.

I contacted our host Linode who reported that "a temporary issue with Google caused some of our default Linode PTR records to be incorrectly flagged with malware warnings". They also reported that Cloudfare has nothing to do with my VPS.

[Sgt_Kickaxe]

*update* it looks like a couple of members had crypto mining software on their PCs they weren't aware of. The mystery isn't solved but one thing the software was doing was loading the Google icon to trigger remote mining start and. somehow, that was causing cloudflare stops to appear. Software removed they aren't seeing coudflare stops anymore.

Other members see it on other sites too, it's not limited to mine, they just hadn't really been looking at many smaller sites to notice..

HOW connections to sites that aren't running cloudflare can still receive cloudflare protection isn't clear yet. Still searching for more answers.

[Kendo]

This week I had a client report error messages that I had not seen before. Googling them suggested that they were Cloudfare errors. But when I suggested that he disable Cloudfare, he reported that it was already disabled. I later discovered that the errors were associated to Cloudfare because Cloudfare uses Nginx. It turned out that Nginx was running on the clients server while running some apps that are not designed for Nginx. This seems to be a common problem with non-technical site owners finding too many toys to play with in their Control Panel.