Redditor thenickdude commented:

> I found that in my hosts file the other day too, and I investigated to find why they're doing it at all.

> They're using this to detect if you have Creative Cloud already installed when you visit on their website.

> When you visit https://www.adobe.com/home, they load this image using JavaScript: https://detect-ccd.creativecloud.adobe.com/cc.png

> If the DNS entry in your hosts file is present, your browser will therefore connect to their server, so they know you have Creative Cloud installed, otherwise the load fails, which they detect.

> They used to just hit http://localhost:<various ports>/cc.png which connected to your Creative Cloud app directly, but then Chrome started blocking Local Network Access, so they had to do this hosts file hack instead.

This is clever in a way, but I wonder what the review process looks like on that team (I say that team because my experience at Adobe was that the company is very heterogeneous).

Novel. A similar approach could be taken by other SaaS tools to comply with age verificaiton laws. Just write an entry to the client's hosts file that points to a subdomain corresponding to a particular birth year. Simple enough for legislative representatives to understand.

/s

The underlying intent here (figure out if it's an existing customer of our locally installed apps when they visit our website) doesn't seem bad, but I certainly dislike both the hosts file and localhost detection options.

I'm curious if there's a "good" way to do this.