This does not come with any version of Firefox install or as an update from Mozilla.

Perhaps this is being installed by one of your Extensions you have installed in Firefox or by a external software you have installed or updated recently.

https://support.mozilla.org/en-US/kb/what-search-hijacking https://support.mozilla.org/en-US/kb/remove-toolbar-has-taken-over-your-firefox-search https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware

Thanks for your reply James. If anyone has any specific information and steps to take to prevent this PUP being installed, I'd appreciate it.

All of the extensions I have are reasonably trustworthy and I would like to try to track down and block startpage from reinstalled.

I am aware of four ways to add a search engine to Firefox:

(1) An extension (2) Manually adding the search engine from the address bar of the search site (Autodiscovery) (3) Enterprise policy (https://mozilla.github.io/policy-templates/#searchengines--add) (4) The undocumented "browser.urlbar.update2.engineAliasRefresh" preference which adds a form to manually create a new search engine from the Settings page.

Since you trust your extensions not to be doing this, I'll skip #1 and mention how to investigate #3:

In the address bar, type or paste about:policies and press Enter to load the About Policies page. Normally, the "Active" panel just says "The Enterprise Policies service is inactive." Does yours list any active search policies?

Thanks It says :|Policy name- Certificates / Policy Value - ImportEnterpriseRoots / true

That policy sets Firefox to trust security certificate added to the Windows system certificate store, so that's not related.

Circling back to what happens at startup, which of these are you seeing (certainly it could be more than one):

(1) Your home page is changed to Startpage.com -- this is the page that appears when you press Ctrl+N to open a new window (How to set the home page)

(2) Startpage.com appears at startup, but not in new windows, only in the active window

(3) Startpage.com appears in every new tab (Ctrl+T)

(4) Startpage.com is added as a search engine BUT it is NOT made the default search engine, it's just one of the icons along the bottom of the autocomplete drop-down when entering a query in the address bar

(5) Startpage.com is added as a search engine AND it is made the default search engine -- when you are typing in the address bar, the top line of the drop-down says Firefox will search with Startpage

Or is it some site other than Startpage.com itself that is misusing its name?

Thanks for taking the trouble to reply in detail.

(1) No the start page doesn't change to 'startpage.com'. New windows + tabs remain blank pages, as set.

(2) Startpage_._com doesn't appear at startup.

(3) Tabs remain blank pages.

(4) Startpage isn't added as a search engine, and neither is it made the default search engine. It just appears as of the icons at the top right of Firefox. (as per image. I've since removed the extension.) My beef is how this extension gets installed, A Mozilla volunteer helper assures me that Mozilla had nothing to do with this.

(5) No. Duckduckgo remains as my default search engine.

My issue is how this extension keeps getting added without my consent.

Hmm, I thought Policy was the only way to force-install an extension.

The next time, before removing it, could you look up where it's stored. That's a little tricky because the path on disk is in a JSON data file, extensions.json. To view the file contents:

(A) Open your active profile folder using the method in this article: Profiles - Where Firefox stores your bookmarks, passwords and other user data

(B) Find extensions.json and drag and drop it into a tab in Firefox. After a few moments, Firefox should present a structured view of the file (you might need to use Expand All).

(C) You can use Ctrl+F to find startpage and then check its path value. ('Note: it's normal for \ characters to be doubled in JSON files, it just means \ to Windows.)

Is it in the normal location ([profile.folder]\extensions) or is it in its own program folder or other unexpected location on disk?

Thanks. No sign of startpage here. Probably because I've removed it. If it installs again, I'll certainly use your method to gather useful information.