Did you get your download from https://www.mozilla.org/en-US/thunderbird/all.html?

The warning from Authentium may be a false positive and hence safe to ignore, but I don't recognize the "2031" hence I'm doubtful about the authenticity of the downloaded file.

Download the full Firefox setup for Windows from www.mozilla.org/firefox/all as some antivirus clients still give false positives on the stub installer even though the newer stub option has existed since Firefox 18.0.

However if you are downloading Firefox and Thunderbird from som download site instead of www.mozilla.org then there is a possibility they are not clean as Mozilla does not host any products on any download sites.

BeachLvr said

Hello, Command Anti-Malware is a provider of anti-virus protection software. It is displaying an alert that "THUNDERBIRD%20SETUP%2031" has been quarantined. The reason is an infection by "W32/Damaged_File.gen!Eldorado". Before installing either Thunderbird or Firefox, can someone describe the risks and how I delete this from my system? Thanking you in advance. Beachlvr

Hi,

When I attempt to download from the Mozilla sites and save a copy of Stub 35.0, the message "Firefox Setup 35.0.exe might have been moved or deleted.".

Update:

I just now tried to download Firefox and Thunderbird from the official Mozzila site. The message that pops up in IE is "Thunderbird Setup 31.4.exe might have been moved or deleted." This same message appears when trying to download either the Thunderbird or Firefox setup programs.

Saving the file does not complete. Here is the most recent file name from an attempt to download the Firefox setup executable: Thunderbird Setup 31.4.0.exe.6smjtgd.partial. This was saved to C:\users\bob\desktop\dowloads\firefox setup according to the Command Antivirus alert. The folder was not created and the download was not successful.

The other interesting fact is the download was for Thunderbird and the folder was firefox.

Finally, a pop-up box message in IE asks "Do you want to un or save Firefox Setup Stub 35.0.exe (237 KB) from download-installer.cdn.mozilla.net?" When I respond with either "run" or "save", the pop-up box message in IE responds "Firefox Setup Stub 35.0.exe might have been moved or deleted."