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Downloaded JPG Files Have Security Warning When Downloaded with FF 14.0.1

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Since updating to FF14.0.1, JPG files that are downloaded from the internet display "Open File - Security Warning" "Unknown Publisher" when double clicked to open. I can disable the warning for individual files, but would rather have it global for all since JPG file are a low security risk. They do open without the warning when downloaded within IE8. I couldn't find any FF security settings that may affect this issue.

Since updating to FF14.0.1, JPG files that are downloaded from the internet display "Open File - Security Warning" "Unknown Publisher" when double clicked to open. I can disable the warning for individual files, but would rather have it global for all since JPG file are a low security risk. They do open without the warning when downloaded within IE8. I couldn't find any FF security settings that may affect this issue.

All Replies (3)

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It's rather unusual for JPEG files to be treated as executable files. Are you sure they aren't disguised executable files? Usually you can confirm by right-clicking and viewing Properties for the file type.

Do you have real-time antivirus software that checks every download automatically when you save it to the hard drive? (If not, you should!) If so, try the following:

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful. This is Firefox's about:config preferences editor.

(2) In the filter box, type or paste scan and pause while the list is filtered

(3) Double-click browser.download.manager.scanWhenDone to switch it from true to false. (One of the features of the scanWhenDone feature is that it marks the file as sourced from the internet, which triggers your IE security zone settings.)

Then go back to another tab and try a new download. Any change?

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"It's rather unusual for JPEG files to be treated as executable files. Are you sure they aren't disguised executable files? Usually you can confirm by right-clicking and viewing Properties for the file type." Yep, they absolutely for sure are plain and simple JPG image files.

"Do you have real-time antivirus software that checks every download automatically when you save it to the hard drive? (If not, you should!) If so, try the following: " Using AVG Free which supposedly checks files on download, although I don't recall for sure if it was compatible with FF14.0.1 now that you mention it.

The suggestion you made allowed a download and double click of the file to open without the warning, so that evidently "fixed" it. I'm just curious as to what may have changed in the new FF version that changed how this worked, as it didn't do this before. I had found some solutions that involved changing the registry, but where IE8 wasn't a problem I didn't want to edit it.

Below is the properties before your recommended change. The security message is clear post change.

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I'm not aware of any changes in Firefox 14 relating to this feature, but there are dozens of changes in each release, so I certainly can't rule it out.

Is the E drive a partition on your hard drive, RAM disk, removable storage? Just wondering whether it might be treated differently than the C drive for some reason. But IE and Firefox should be consistent, since this is all about Windows' internal security controls...