Seeing ads on Wikipedia? You may have malware

WikipediaWikipedia has issued a warning to its many millions of daily visitors that if they are seeing commercial adverts on its webpages, that it may be an indication of a malware infection on the user’s computer.

Criminals aren’t shy of earning affiliate cash by injecting unwanted adverts into webpages or redirecting users to sites or search results that innocent users didn’t mean to visit.

Despite its colossal popularity, Wikipedia has always resisted putting ads on its pages. The site prefers to ask the public for donations and runs fund-raising campaigns from time-to-time.

As Wikipedia explains in its official blog:

Sign up to our free newsletter.
Security news, advice, and tips.

We never run ads on Wikipedia. Wikipedia is funded by more than a million donors, who give an average donation of less than 30 dollars. We run fundraising appeals, usually at the end of the year. If you're seeing advertisements for a for-profit industry (see screenshot for an example) or anything but our fundraiser, then your web browser has likely been infected with malware.

Injected advert on Wikipedia

So, if you begin to see adverts in unexpected places on the net, check your browser’s plugins and disable any add-ons and browser extensions that may be causing the problem.

In addition, run an up-to-date anti-virus to make sure that whatever might have introduced the unwanted ads isn’t also up to other malicious behaviour behind the scenes.


Graham Cluley is an award-winning keynote speaker who has given presentations around the world about cybersecurity, hackers, and online privacy. A veteran of the computer security industry since the early 1990s, he wrote the first ever version of Dr Solomon's Anti-Virus Toolkit for Windows, makes regular media appearances, and is the co-host of the popular "The AI Fix" and "Smashing Security" podcasts. Follow him on Bluesky, Mastodon, and Threads, or drop him an email.

What do you think? Leave a comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.