4 Ways To Defend Against Malvertising

Malvertising is a portmanteau of “malware” and “advertising”. Malware distributors use web advertisements to infect visitors’ devices with malicious code. They buy up advertising space on unsuspecting websites and use it to deploy advertisements loaded with unwanted and often illegal programs. These can include Trojan horses, cryptominers (programs that hijack your CPU to mine cryptocurrency), programs designed to steal sensitive information such as account logins and bank details, and ransomware.

Some kinds of websites are especially high-risk for malvertising. Unlicensed streaming sites, torrent aggregators and adult sites are particularly notorious. Even if you browse responsibly and avoid risky sites, however, there’s no guarantee that you’ll avoid running into malvertising. While responsible distributors try to avoid hosting malvertising on their sites, malware distributors can circumvent their efforts by posing as ordinary advertisers. They may deploy normal, uninfected ads for weeks or even months before switching to ads containing malicious code. These ads can wreak havoc even if they’re only in place for a short time, infecting tens of thousands of visitors in the case of high-traffic sites.

Clearly, it’s important to protect yourself against malvertising. Here are a few steps everyone should take to avert this kind of threat.

1. Install and run effective anti-malware utilities, including anti-exploit utilities that protect against threats like Trojan horses.

2. Enable click to play for Flash and Javascript content. Many malicious ads rely on scripts and vulnerabilities in Flash to spread – it’s best to only allow this type of content to play if you’re confident everything’s secure.

3. Download a good adblocker and run it. Not only will this protect against malvertising but it can also make for a smoother, less annoying browsing experience.

4. Pay attention to your computer’s overall security. If you don’t need Flash or Javascript, disable them. Update your OS and keep it patched — the same goes for all your other software. In particular, any browsers you use need to be kept up to date.

It doesn’t take too much effort to make your device much safer from malicious advertising. Take these simple steps today and stay malware free tomorrow.