Sounds like external malware, which launches pages in your default browser from outside Firefox. If you change your default browser to IE, do the pages start opening in IE?

Last year, many users reported advertising tabs opening randomly, sometimes even when Firefox was closed. It turned out that a program had created scheduled tasks to open those pages at certain times of day.

You can check the Windows Task Scheduler:

• Windows XP: Start button > [All] Programs > Accessories> System Tools > Scheduled Tasks

• Windows Vista/7: Start button > Control Panel > System and Security > Administrative Tools > Task Scheduler

• Windows 8: ?? You might try the charms bar search box if you don't find it in the control panel.

• Past threads on the "dsite" problem:
  • How can I keep Firefox from opening a window to website tofushopnews.com
  • How do I get rid of sponsorship tabs that open automatically?

Also, you may want to use some of the other malware scanners listed in our support article: Troubleshoot Firefox issues caused by malware.

I haven't tried using IE as the default browser. I will look for task scheduler in windows 8.1. I will repost my findings. Thanks

I changed my default browser to IE and it did the same thing as Firefox. Website: http://www.big-countries.com/ I have also checked task scheduler and does not appear to be any tasks running that shouldn't be.

I think the next step would be the extra malware scans.

It could be the work of one of your add-ons, or even add / mal-ware. Look thru your add-ons list and make sure you know what each one is there for. Also, check the programs that are on your computer

Windows: Start > Control Panel > Uninstall Programs. Mac: Open the "Applications" folder Linux:

• Ubuntu Unity {web link}
• Xfce: Applications Menu category sections
• options depends on the package manager and the desktop environment

Go thru the list. If you find something that you don't know what it is, use a web search.

Troubleshoot Firefox Issues Caused By Malware {web link}