This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Found secret hidden Firefox browsed screenshots

  • 4 replies
  • 2 have this problem
  • 1 view
  • Last reply by cor-el

more options

I primarily use Firefox as my browser on my newer iMac with mountain lion. I had accidentally deleted some family photos from my desktop and used a recovery tool program to scrub my hard drive for recently deleted images. The program worked very good as I was able to recover my deleted family pictures but I had to go through hundreds of images to find them. In those hundreds of images I went through, I found screenshots of my Firefox activity from banking sessions, to amazon shopping, to google searches. I was stunned. They were only screenshots of Firefox browsing sessions. Hundreds. All taken without my knowledge. I clear my data often on Firefox. Cookies, cache, history, etc. I clear everything. Does anyone know why this is happening and how to stop it? It's definitely a security issue, a lot of the screenshots even showed "sign on" screenshots of banking sessions and amazon user names, email log-ins, etc. I don't know where the screenshots are stored, like I said I used a deleted image recovery program and it doesn't tell you, it just finds files. I scoured my computer looking for jpgs, pngs, etc and couldn't find anything on my own.

I primarily use Firefox as my browser on my newer iMac with mountain lion. I had accidentally deleted some family photos from my desktop and used a recovery tool program to scrub my hard drive for recently deleted images. The program worked very good as I was able to recover my deleted family pictures but I had to go through hundreds of images to find them. In those hundreds of images I went through, I found screenshots of my Firefox activity from banking sessions, to amazon shopping, to google searches. I was stunned. They were only screenshots of Firefox browsing sessions. Hundreds. All taken without my knowledge. I clear my data often on Firefox. Cookies, cache, history, etc. I clear everything. Does anyone know why this is happening and how to stop it? It's definitely a security issue, a lot of the screenshots even showed "sign on" screenshots of banking sessions and amazon user names, email log-ins, etc. I don't know where the screenshots are stored, like I said I used a deleted image recovery program and it doesn't tell you, it just finds files. I scoured my computer looking for jpgs, pngs, etc and couldn't find anything on my own.

Chosen solution

hello Butthump, what you are seeing might be the thumbnails created for the default new tab page.

to disable the creation of cached thumbnails generally, enter about:config into the firefox location bar (confirm the info message in case it shows up). right-click somewhere in the page and create a new boolean preference named browser.pagethumbnails.capturing_disabled set to true.

https://developer.mozilla.org/en-US/docs/Mozilla/Preferences/Preference_reference/browser.pagethumbnails.capturing_disabled

Read this answer in context 👍 3

All Replies (4)

more options

Chosen Solution

hello Butthump, what you are seeing might be the thumbnails created for the default new tab page.

to disable the creation of cached thumbnails generally, enter about:config into the firefox location bar (confirm the info message in case it shows up). right-click somewhere in the page and create a new boolean preference named browser.pagethumbnails.capturing_disabled set to true.

https://developer.mozilla.org/en-US/docs/Mozilla/Preferences/Preference_reference/browser.pagethumbnails.capturing_disabled

more options

Thanks for replying so quick. I took your advice and disabled the thumbnail capturing. Do you happen to know where the thumbnails are stored on my mac? There has to be a thumbnail cache folder or something right? I would like to delete anything it has saved. Thanks.

more options

i don't have a mac myself, so i cannot verify it, but according to some sources on the web, they'd likely be at ~/Users/<USERNAME>/Library/Caches/Firefox/Profiles/<XXX.default>/thumbnails

the Library folder might be hidden by default
http://www.macobserver.com/tmo/article/mavericks-easily-make-user-library-folder-visible
http://osxdaily.com/2011/07/22/access-user-library-folder-in-os-x-lion/

more options

You can find the location of the disk cache on the about:cache page (open this page via the location bar).
If you go back one level (i.e. remove the trailing Cache) then you should see the thumbnails folder listed.