OISjpegfile on Windows 7?

Question

Windows

Today they threw off a couple of pictures, but when I tried to open them, Windows suggested choosing a program. JPG file extension. I opened it through Notepad++ and saw Apple's XML there: habreffect.ru/files/2c3/cfa1e94b4/Snapshot.PNG In the properties of the photo it was written File type: OISjpegfile (.jpg). I decided that just the author of the photo uses a Mac, and he, in turn, converts the images in this way. But later I noticed that all my pictures with the JPG extension also became OISjpegfile. wtf? I don’t have Apple products, I didn’t install new programs, I’m sitting under a simple user. OS Win 7 sp1, Casper 11 (didn't find anything).
Actually I wonder if I should run and shout “AAA!!! We all die!" or just assign a program for JPG pictures and not take a steam bath? It's a little annoying that the file type has changed without my knowledge.

Answer 1

I got into the registry, changed the default value for jpg, jpeg, bmp formats from OISjpgfile, OISjpegfile, OISbmpfile to jpgfile, jpegfile, bmpfile respectively. It looks like ois.exe from Office 2003 is somehow involved. Deleted the office, cleaned the registry (a lot of errors related to ois.exe), reinstalled the office. Seems to work =)