Recently, upon visiting my Slanted Viewpoint blog, I was shocked to see an advertisement at the top of the page. I had never selected, modified, or added anything to my blog's settings that might have caused ads to start appearing. What the heck was going on?
Making matters worse, the ad covered over article text, requiring readers to dismiss the ad before they could proceed. Plus, the ad was for cosmetic products, which is completely unrelated to anything I had ever written or would ever write about. I was now angry as well as shocked.
My blog is created with Wordpress. After some investigation, I learned that Wordpress may occasionally insert ads in Wordpress-generated blogs. To prevent this, you need to pay $30 per year.
I had not paid this fee. Could this be what was behind the ads on my site? I was skeptical. First, despite the warning, I had never previously seen any ads. Second, the ads were not merely "occasional"--the exact same ad appeared with every reload. Third, I doubted Wordpress would ever allow such an intrusive ad placement. So I delved deeper.
Shifting from my Mac Pro, I checked to see if the ads also showed up when I loaded the blog from my MacBook. They did not. It soon became apparent that my desktop Mac was perhaps the only Mac in the universe that was showing the ads. This was both good news and bad news. The good news was that I didn't have to worry about other people being annoyed by the ads. The bad news was that my Mac Pro appeared to be the victim of some sort of malware attack.
On my Mac Pro, I had been using Safari. I now went back to see what would happen in other web browsers. I launched Firefox--and was immediately greeted by a message asking if I wanted to allow the installation of an add-on named Photozoom!
Aha! I recalled seeing the word "Photozoom" in tiny text as part of the nefarious cosmetics ad. I was zeroing in on the culprit. I declined Firefox's invitation and returned to Safari.
I went to Safari's Preferences, selected Extensions, and began scrolling down the list of installed items. There it was: Photozoom V9.0 1.25. I clicked the Uninstall button and returned to my blog. The ads were gone.
There is a legitimate Photo Zoom extension. It works within Facebook to enlarge images as you hover over them. The malware is masquerading as the real Photo Zoom. The two have nothing in common beyond their nearly identical names.
As far as I know, I've never installed either extension. Apparently, Safari (unlike Firefox) had allowed the malware to be installed without requiring my explicit permission. Not good. But at least I had put a stop to the intrusion. End of story. Case closed. Almost.
Two critical questions remained unanswered: Where did this malware extension come from and how did it get on my computer? I don't know for sure. And I probably never will. An Anvisoft page suggests that the most likely source was either opening a phishing email attachment or visiting a website that hosts the malware. The Anvisoft page also gives advice about additional actions to take beyond simply uninstalling the extension. The goal is to make sure there isn't any residual malware elsewhere on your machine. Although focused on Windows PCs, it's worth a read even for Mac users.
Lesson learned. Going forward, I intend to be even more cautious about opening emails that are at all suspicious as well as visiting unfamiliar websites. The Mac may not be nearly as vulnerable as Windows PCs to the viruses and malware lurking on the Internet. But, as this incident shows, the risk is still greater than zero. Be careful out there.