Yahoo Security Alert Hoax: Important, Please Read.

[Gore1FL]

When not logged in, I have been getting a “Yahoo Security Alert” full page “Ad.” Requesting credentials.

This is a hoax.

If you get this pop, hit the back arrow. DO NOT PROVIDE CREDENTIALS!!!!

It has appeared multiple times for me while simply reading DU posts. Signing in as a Star Member eliminates this. If that is not an option, please be aware of the phishing and ignore it—unfortunately, that strategy may make (parts of/all of?) DU unusable as the pop-up keeps returning as the ads refresh.

[CousinIT]

1. Try UBlock Origin

It's an ad and popup blocker.

[usonian]

2. Most malware piggybacks on ads.

An ad-blocker is not just an eye saver and speed booster, it's a necessary safety measure in this hostile internet.

https://www.theguardian.com/commentisfree/2011/oct/24/advertising-poison-hooked

From 2011,
Advertising is a poison that demeans even love – and we're hooked on it
George Monbiot

[Sector 001]

3. Just install Ublock origin and you will not see that crap.