Oh wow. You can’t even trust your printer now ‘cos it could expose potentially incriminating information about how you are using it.
The problem is that most new printers print nearly invisibly yellow dots that track down exactly when and where documents, any document, is printed. Because the NSA logs all printing jobs on its printers, it can use this to match up precisely who printed the document.
Source: Errata Security: How The Intercept Outed Reality Winner
It got me paranoid when I notice the blink-and-you-miss opening and closing of a popup ever so often when using Windows 10. After turning on process audit I finally managed to track it down to officebackgroundtaskhandler.exe. Turns out it is due to Ms Office doing some who-knows-what background handling. Follow the article below to disable the annoying popup.
If you run Microsoft Windows 10, you may have noticed a popup window being launched on the screen once a day, or even regularly.
Source: What is that popup on Windows 10 that disappears after a split second? – gHacks Tech News