The FBI warned that cyber crims were using online ads in search results to steal or extort money from victims.

They were buying ads to impersonate legitimate brands and these were being placed at the top of search results but with "minimum distinction" between the ads and the search results.

Malicious ads are also used to trick victims into installing malware disguised as genuine apps, which can steal passwords and deploy file-encrypting ransomware. One of the FBI's recommendations for consumers is to install an ad blocker.

What is funny is that advertising is the way that legit sites make money and keep going. Some companies have installed paywalls to make sure that the money still arrives or insisted that the adblocker is turned off when visiting their site.

Ad blockers have become popular because they remove bloat from websites, like auto-playing video and splashy ads that take up half the page. They also prevent the tracking code within ads from loading.

"Of course, you can switch your ad blocker off any time you want, and even allow or deny ads for entire websites," adds the report.