Running Windows 7 Home Premium, Service Pack 1 on an HP desktop. I happened to have my Documents library sorted by date modified, to keep the folder I was using at the top of the list. Suddenly 6 random folders show up at the top of the list, all with a date and time stamp of 8/23/14 2:27pm. I had not touched any of these folders, and I noticed this about a half hour after that timestamp.
I am concerned because one of the folders had bank statements and the other some Social Security application information. The other 4 folders were just benign like recipes. Also, in that time while I was working, I had recently saved a file to Google drive, to make it available to me from other computers. That file was not in any of these 6 folders. Unfortunately, I do share my Documents library on my Homegroup (and I have since changed that...)
What could change the date modified on those folders? It seems like more than a coincidence that this happened right after I saved a file to Google drive, and that two of the folders had information that I wouldn't want to be public.
I ran a virus scan (Windows Sec Essentials) and Malwarebytes and nothing shows up. By the way, I have hundreds of folders in my Documents library, so just having 6 of them change is weird.