An FBI officer using a laptop.

The Federal Bureau of Investigation took a break from hunting serial killers this week to post a public service announcement.

Criminals are using ads in search engine results to impersonate brands, according to the internet crime complaint center. The ads send users to fake websites that look similar to the pages they are actually looking for, where they can be victims of cyberattacks. An ad blocker can help, according to the bureau.

The government doesn't recommend any particular ad blocker, but I just tested it with a few of my favorite searches and it didn't show any ads. If you find yourself in the comments section of the article complaining about the ads on Gizmodo, you can use an ad blocker.

People tell me they're too smart to fall for online scam. This is the kind of attitude that makes you lose money. If you think you aren't vulnerable, then you're at risk. It takes a single click to get into trouble.

The FBI recommends fail-safes such as checking the URL of the page you're visiting, or typing in the web address directly instead of searching it. In the area of finance or cryptocurrencies, the FBI says these are the most common types of scam. It's a good idea to be extra careful when you're online.

When you click on an ad, you should pay attention to the search results. This is an increasingly annoying prospect, as services like Google work hard to make their ads look like regular search results, and often fill up the first screen of results with ads, making you scroll down to find what you really want.

If you're a victim of a scam, the FBI would love to hear from you. If you want to talk to the feds, you can report the crime to your local FBI field office.