The Malware Prize: You Don’t Want It

Q: I keep getting these “Congratulations!” messages about winning prizes from Amazon.com, even when I’m not using the site. Why is this?

A: Those persistent pop-up messages are not from Amazon, but are part of a wave of malicious display advertisements — also known as “malvertising” — invading desktop, Android and iPhone browsers. The intrusive ads can also appear when browsing links that are posted on Facebook.

Malvertising has been a problem for years, but lately has become more pervasive on mobile devices. Symantec, a security company, noted this year that the “congratulations” malware has been making a strong push onto Android devices with a Trojan horse called Android.Fakeyouwon.

In January, the cybersecurity company Confiant also outlined how the recent malware was spread across the web by fraudulent advertising agencies, which placed tainted ads on legitimate sites. If you select the pop-up’s OK button or try to dismiss the box, the browser is typically redirected to a page that promises prizes for participation in a quiz.

Interacting with the quiz may infect your system with malware or give the scammers access to your Facebook friends list. If you get a “congratulations” box on your screen with no way out, forcibly quit the browser to escape.

If scam messages are regularly popping up on your screen, your computer or device may be infected. To disinfect your system, run an anti-malware utility like Malwarebytes AdwCleaner for Windows; Malwarebytes for the Mac scans for adware, too. Microsoft has a Malicious Software Tool for Windows. Apple’s support site has guides for blocking pop-ups in the Safari browser and clearing the history and website data from an iOS device.

The Facebook Help Center has instructions for dealing with malicious software. Google recently added new security features to its Chrome browser for desktop systems and Android to help remove pop-ups and malware, and Mozilla’s site has a malware-troubleshooting guide for Firefox.

Q:I wish to import a PDF file to accompany my post in Facebook. Can this be done?

A: Facebook allows its members to attach and upload PDF files to posts only under certain circumstances — and not on personal profile pages. If you have a Facebook business page for a restaurant, you can upload the menu as a PDF file. To do so, go to the page, click About on the left side, go to the More Info area, click Add Menu and select the PDF of your menu.

You can also share a PDF file with the other people in a Facebook Group. To do that, go to the Group page, click the More button, select Add File and choose the PDF document to upload. On the left side of the Group page, you can also click Files and then Upload File to add the PDF document.

While Facebook may limit uploads for personal pages to photos, videos, animated GIF files and web links, you have other ways to share the content of the PDF file with friends. For something like a single-page poster or form, saving the PDF file as a JPG photo allows you to post an image of the document as a picture; you can convert it for free with the Mac’s Preview program or the PDF to JPG app for Windows. Taking a screenshot of the open page is another way to create a picture of it to post.

If it is a more complicated file, like a multipage document or an interactive form, store it on a file-sharing site like Dropbox or Microsoft OneDrive. Once the file is online, create a public link for sharing and then post that link on your Facebook page.