Malicious ads are spreading faster than ever, and ad blockers aren’t just about making browsing less annoying anymore. These days, they’re turning into one of the easiest ways to stop your computer from picking up something nasty.
For years, most people saw ad blockers as convenience. No one wants their screen cluttered with blinking banners or a video blaring out of nowhere. But things have shifted. Security experts now see an ad blocker as a real line of defense, not just a comfort setting, and the change makes sense.
It’s pretty straightforward. Ad space is wide open for attackers, and online ads have turned into a prime spot to deliver malware. The numbers back it up, malicious ads aren’t slowing down, they’re taking off.
Malicious ads are surging, not slowing down
Malvertising, where hackers hide malware or phishing tricks inside seemingly normal ads, has been around for a while. What's different is the scale. According to Help Net Security, malvertising shot up by 42% in 2025 compared to the year before. That’s the biggest jump in a single year since 2019. And it lines up with how big the ad business has gotten.
Global digital ad spending hit $740 billion in 2025. That means way more chances for criminals to slip their stuff in. One bad ad can end up on thousands of sites through the same ad networks that push legit campaigns, which is partly why it’s so tough to root out.
Ads have become a primary delivery method for malware
Here’s a fact a lot of people outside security don’t realize: Ads aren’t just a minor leak for malware anymore. They’re a main pipeline. A study referenced by Cybersecurity Insiders found that nearly 60% of malware and phishing incidents in 2025 tied back to online advertising one way or another.
And it’s not just sketchy websites. The same research shows bad ads have made it into connected TVs, streaming apps and retail media networks: Basically, if there’s a screen showing ads, there’s a way in. Browser tabs aren’t the only target.
Take these two incidents from last year. Microsoft Threat Intelligence spotted a massive malvertising campaign in 2025, compromising almost a million devices globally. Hackers used ads on illegal streaming sites to funnel victims toward malware stashed on GitHub, a place most people wouldn’t think to be suspicious of.
Then you’ve got GhostCat, also known as ScamClub, which doubled its video ad placements in early 2025. The Media Trust’s CYA 2025 report called this out because, for a long time, people thought video ads were safer. Clearly, that assumption doesn’t hold up anymore.
Why blocking ads cuts off an entire attack path
Ad blockers don’t solve every security issue, and nobody should expect them to. But they do remove a step attackers depend on. If the ad never loads, the malicious script or redirect hidden inside it doesn’t get its shot. This matters most with those “forced redirect” attacks, where you don’t even need to click anything.
Just landing on a page with a nasty ad can send you to a scam site or hit you with a fake security warning. So, cutting off ads at the browser level closes that door before you even see it.
Ad blocker adoption reflects this shift. GWI data shows about 29.5% of internet users worldwide used ad blockers in the second quarter of 2025. That’s around 1.77 billion people. In the U.S., it’s around 32.5%, and that figure just keeps climbing as folks get more aware of how risky ads can be.
What this looks like in practice
Most modern ad blockers filter out ad requests before a webpage even loads, relying on lists of known ad servers and trackers to decide what makes it through. Some tools go a step further and strip out tracking scripts, cutting down on data about your browsing habits along the way.
Take PoperBlocker as an example, a browser-based ad blocker focused on zapping ads, pop-ups and trackers while pages are still loading. Tools like this fall into a bigger category of lightweight, browser-level filters that more and more people install alongside antivirus software, not as a replacement.
That’s important. Ad blockers are not a substitute for antivirus or good online habits. They’re a bonus layer, knocking out risks before your main protection even gets involved.
Don't panic
Not every ad is dangerous, most aren’t. But the odds have changed enough that treating ad networks as safe, low-risk parts of browsing just isn’t realistic.
Malvertising spiked bigtime in 2025, and incidents like Microsoft’s million-device campaign or GhostCat’s video ad surge prove how creative attackers are getting. Blocking ads has become more than a nice convenience, it’s closer to a basic need. For anyone serious about computer security, ad blockers are an easy, low-effort step to close off one of malware’s favorite pathways into your machine.