This is being caused by Javascript that is being injected via an ad that appears on the page you are visiting at the time. It can happen on perfectly legit sites. I saw one appear when I loaded XDA Developers.
There is no way to "clean" it from your computer because there is nothing to clean.
Amazonaws.com is a cloud-based service that serves ads, among other things. The service itself is legit- many companies use Amazon's cloud to store and serve advertising- but one of the advertisers is, obviously, rogue, and is using the s3 subdomain to serve ads loaded with misleading Javascript that opens up a (in my case) new tab in Chrome.
This has happened on all of my devices, desktop and mobile. No scan of any kind reported any infection, including a browser hijack.
I was able to block at least some of these by placing a domain reject blacklist entry of *.amazonaws.com in my router's domain blocking table. That, however, works only for when I am connected to my home wifi.
More recently, I've been getting the "This is a message from Microsoft. Your computer has been affected by virus" computer-voice pop-up scam (the one with the 800 number to call "Microsoft"). Again, that is also caused by deceptive/malicious Javascript injection via an ad or in the page itself. While annoying, that's ALL it is if you click no links and "check this box to prevent the page from creating additional dialogs", then close the tab.
Don't run around wasting time looking for a way to remove the" virus". You don't have malware, and no, your browser has not been hijacked. Sites claiming a sure way to remove such due to this issue are, very likely, themselves trying to scam you (which is likely to be the point of the pop-ups themselves!).
Don't believe ANYTHING bleepingcomputer.com says about this. They will waste hours of your time, have you scan and install their "tools" literally for days on end, and you will make exactly zero headway with this issue. Those people do NOT know what they're doing, at all.
What we SHOULD be doing is contacting whatever customer service Amazon has set up for their cloud services, because one of their customers is the source.