# Windows Defender blocking Vivaldi

• I've been using Vivaldi for many months - without issue

All of a sudden, Windows Defender is blocking vivaldi

I add Vivaldi app data to the exclusions and it made no
difference.

Will really appreciate assistance... Vivaldi is my favourite
browser

thanks
Karen

• Why is Defender blocking? Any message and hint in Defender app log?

• windows7 + defender make no problems, so eventually you have windows 10?

• I guess Defender reports a false positive.

• No problems with Defender here - Win 10 Pro (64 bit)
Using Vivaldi 1.14 Stable (32 bit) and 1.15 Snapshot (64 bit).

• Sorry - yes - Windows 10/64 Pro - been using Vivaldi for many
months on 3 computers... this is the first time with a problem

Vivaldi browser went completely black. I couldn't see anything
so had to just close the browser...

I checked to see if there was a Vivaldi update and my browser
is current.

I think that i rebooted my computer and when I started the
browser again, it just closed and kept closing each time

I clicked "run as administrator" and that's when i saw the
Windows Defender notice..

Virus and Threat Protection

Unauthorized changes blocked
Controlled Folder Access blocked C:
\Program ...\Dropbox.exe from making
changes to the folder %userprofile%
\Desktop

another one reads the same as above -
except for \Dropbox.exe...

I have absolutely NO idea what that means
or how it relates to Vivaldi

Will greatly appreciate some insight/input

Thanks
Karen

• The Threat Alert displays Trojan: Win32/Tiggre!rfn

Karen

• "Controlled Folder Access" is a new feature in the latest versions of windows 10, and I don't believe it is turned on by default.

You use it to write-"protect" access to certain folders to prevent things like crypto lockers from changing them. It means that you need to manually whitelist any files that try to use that directory.

You'll need to verify which folders are listed under "controlled folder access" in defender, and if vivaldi (or dropbox, as in your example) wants to write there, you'll need to manually whitelist vivaldi.exe

Additional note: I believe the exclusions from controlled folder access are different to the general defender exclusions.

2. In Explorer open %LOCALAPPDATA%\Vivaldi\User Data\Default\
3. Delete files Last Tabs and Last Session and Current Tabs and Current Session
4. open %LOCALAPPDATA%\Vivaldi\User Data\Default\Cache\
5. Delete all files
6. Start Vivaldi

• @ThisProductRocks, the question arises as to why the website was attempting to download something(s) onto your Windows user-account's desktop folder in the first place. That is apparently a CFA-protected folder (at least on your system) and that action is what the 'error' messages are flagging. The actions are being re-flagged each time you've tried to restart Vivaldi, since they have been stored in the tabs/sessions files of Vivaldi and attempt to reassert upon each Vivaldi restart. Whether the detected Trojan malware is valid or a false-positive is its own issue. At this point, you need to clear out the Vivaldi tabs and sessions files as @Gwen-Dragon suggests in order to be able to cleanly restart Vivaldi without re-triggering the Windows blocking actions.

Then you need to establish whether the intended download is clean or infected, and whether in the future you want such things coming directly to your desktop (in which case, you need to create a whitelist exception in the CFA listing for the program(s) - keeping in mind that such whitelisting will thereafter always allow the whitelisted program(s) unfettered access to files in your desktop folder).

• @gwen-dragon .... thank you.... I followed your directions and
Vivaldi still closes immediately ;(

Karen

• @lonm thank you...

I'm not aware of/remembering turning the "controlled folder access" option on...

vivaldi.exe

Rebooted my computer and Vivaldi works!!!!!!!!!!!!!!!!!!!!!

Thank you everyone for your help... can't / don't want to try working without
Vivaldi :)

Karen

• @thisproductrocks oh well....

Vivaldi stayed running for a few minutes... and it's closing immediately again ;(

any other recommendations???

thanks
Karen

• Have you checked with Windows Defender again to see if there are different blocking messages there now?

• @blackbird I checked Windows Defender and there is no longer any
messages at all. just won't allow Vivaldi to start ;(

thanks
Karen

• @thisproductrocks Try refreshing your profile altogether and see if that makes any difference.

• I just spent almost two hours with a Windows tech person - working
remotely on my computer

He went through all of the defender settings... added/changed settings...

Rebooted several times... after each reboot, Vivaldi would start and sit -
open - for quite some time... when I minimized the browser to taskbar,
it would shut down.

Anyone else have any ideas?

Thank you many bunches

Karen

• after each reboot, Vivaldi would start and sit -
open - for quite some time... when I minimized the browser to taskbar,
it would shut down.

When Vivaldi is minimized does this happen if you have a site open or without any Vivaldi tab or window?

Do you have extensions installed in Vivaldi?

May be it is one of these issues (known, fix in progress) where Vivaldi consumes RAM and will be terminated by Windows.

• Vivaldi is installed on two of my other computers as well -
all with Windows 10/64 Pro

All of the browsers had exactly the same extensions installed on
them.

I had used OneTab to close/save all of the open links and when
restarted, that's all that shows up - the onetab pages.

once again, Vivaldi does not stay open long enough to do anything
at all...

This is such an awesome browser

thank you
Karen

• All of the browsers had exactly the same extensions installed on
them.

And Vivaldi 1.14 Stable crashes on all these PCs after a short time?

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