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.

Avatar for Username

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

This thread was archived. Please ask a new question if you need help.

A curious file in Program File\Mozilla Firefox folder

SafeBrowser
SafeBrowser
more options

A curious file has appeared in my Program Files\Mozilla Firefox folder named: firefox.exe__ (yes, with 2 underscores after the name). It is 2,560 bytes in size and has a "Modified Date" of June 21, 2010 4:37:05 PM. Also on the Windows right-click Properties dialog is a note at the bottom in an area labeled "Security": "This file came from another computer and might be blocked to help protect this computer" with a button to "Unblock" is I so choose.

Of the 43 scan engines on Virustotal.com, only one (McAfee-GW-Edition 2010.1C 2010.11.17) shows it as suspect: Heuristic.BehavesLike.Win32.Spyware.J

Has anyone else seen this? Any clues?

A curious file has appeared in my Program Files\Mozilla Firefox folder named: firefox.exe__ (yes, with 2 underscores after the name). It is 2,560 bytes in size and has a "Modified Date" of June 21, 2010 4:37:05 PM. Also on the Windows right-click Properties dialog is a note at the bottom in an area labeled "Security": "This file came from another computer and might be blocked to help protect this computer" with a button to "Unblock" is I so choose. Of the 43 scan engines on Virustotal.com, only one (McAfee-GW-Edition 2010.1C 2010.11.17) shows it as suspect: ''Heuristic.BehavesLike.Win32.Spyware.J'' Has anyone else seen this? Any clues?

All Replies (2)

the-edmeister
the-edmeister
  • Moderator
more options

That file is too large to be a legitimate firefox.exe file, which are around 890kb for 3.5 & 3.6 versions. Right-click that file and open Properties, then look at the Version and Digital Signature tabs.

SafeBrowser
SafeBrowser Question owner
more options

Thanks for the reply.

No, the file is 2,560 bytes, not kbytes.

There is no "Version" tab in Properties; only "General", "Security" and "Summary" tabs. General tab shows usual information (3 dates, size, etc.) plus the "Security" information in my original question. Security tab shows users on my system (the usual ones that are valid) and Permissions (nothing out of the ordinary. Summary tab is all blank.

Have copied the file to another name, deleted original file (Shift+Delete so it did not go to the Recycle Bin) with no negative effects. Registry shows the path and the original file in the MRU list --- very curious.

Ever seen anything like this before?

Modified by SafeBrowser