Sandboxie fails to purge Sandbox - ACCESS DENIED error on delete invocation

Hi Carbonyl,

This is a fairly common scenario, and it is usually triggered by AVs holding on to files. 

A few suggestions:
-Try a leader program setting for Chrome https://www.sandboxie.com/ProgramStopSettings#leader
-Add Sandboxie to the AVs exclusions and see if that helps. 

The last option is what you already figured out, a reboot takes care of whatever is holding on the files and allows Sandboxie to empty the contents. 

Regards,

Hi Barb,

Thanks for the fast reply. I very much appreciate the information. Just to be clear, does the frequency of this issue indicate it's fairly benign? It's the first time I've seen it, and it has me quite worried.

To respond to your suggestions:

-At present the sandbox in question already has Chrome as a leader program. The sandbox was configured this way before the issue occurred, and the settings are still configured that way. From what I can tell, no processes are running in the sandbox at all when this error is encountered.

-I believe I had already added Sandboxie to the exclusions list in ESET, but I will verify that once I get home from work to check on that today.

As an additional question: Is there any way to determine what program is holding on to RegHive? It seems to be quite persistent, but I can't find out what program is doing it in this case.

I'd prefer not to have to reboot my computer every time I want to purge the Sandbox!

Thanks very much for your help on this matter. I will also update as I learn more.

I just wanted to note that I have reached out to ESET support about this. I've provided them with log files and am awaiting a response.

Carbonyl Stretch said:

I just wanted to note that I have reached out to ESET support about this. I've provided them with log files and am awaiting a response.

 

Ironically, I've also contacted ESET about this as well detailing how ekrn was holding onto said hive / preventing an unmount {effects both Chrome and Palemoon for me}.  Got a response on the 5th.

This is what they sent me per my case: {Sandboxie "Access is Denied", when deleting sandbox contents}

An ESET Technical Support Representative has updated this case with the following information:

Hello,

Thank you for contacting ESET North America Technical Support.

To exclude an application or IP address from protocol filtering from ESET Windows home products, visit: support.eset.com/.../

Thank you for using ESET security products,
ESET Technical Support
North America
------------------------------------------------------------------------------
ESET Knowledgebase | articles | videos | manuals | support
http://support.eset.com/

Needless to say, excluding the Sandboxie processes under web protocol filtering had no effect in mitigating the issue {nor realtime protection exclusions -- though disabling NOD32 realtime protection "completely" does work}.  I'm also waiting per round two going on ~72 hours since that last reply.  Please do keep the thread updated if you find out anything.

To add a bit more, even if the Sandboxie service is forcefully killed and regedit is launched as "SYSTEM" -- that's still not enough to unmount the hive.  {NOD32 still hangs onto it}

-- Best I've managed to do right now is flushing everything with the exception of the hive, manually, as even disabling realtime protection {post incident} the hive file is still not released.

Hi all,

While you wait for the AV team to reply to you, I have some suggestions

Try deleting the Sandbox folder manually via Safe Mode. Then, reboot to normal mode, and if present, remove the ESET template from Sandboxie (Configure -- Software Compatibility --> Uncheck the ESET template) . Re-test the behavior with a new Sandbox (if this fails, or causes other problems, please re-add the template).

Since you mentioned Ekrn.exe , you may want to try blocking that file in the Sandbox and test what happens (it may or may not work, as it it may trigger error messages).

Right-click on your Sandbox
Sandbox settings---> Resource Access ---> File Access --> Blocked access
Add the following entry:
*\ekrn.exe
Ok and Apply
Re-test

Remove the changes if they don't help/cause problems.

Regards,

Good morning, I have the same problem.
I can not delete the sandbox since the "RegHive" file remains in use after closing all processes.
Do you know if it will take a long time to solve this problem?
I use this application a lot and with this failure it is not operative.

Thank you

Barb@Sophos -- unfortunately the suggested changes did not help.  (removal of ESET from software compatibility, and attempted blocking of ekrn through Sandboxie settings)

-- Lucas, are you also using NOD32 as your AV solution?

So far all responses that I have gotten from ESET have not been promising (getting the runaround), as they have not acknowledged a problem nor the intent to fix said problem.

Disabling components within NOD32 selectively, such as shutting off HIPS or ransomware protection doesn't help ... only complete disabling of NOD32's realtime protection seems to resolve the issue.  Short term, if you rely heavily on Sandboxie I would suggest that you temporarily swap AntiVirus Software.  Of course, you should also open a support ticket with ESET support, so that they see that this impacts many people and it gets escalated.  (I've also tried calling them, though yes the more they hear of this the better -- given it's something they pretty recently broke)

For the record, I went back over to Avira while waiting.  {as I'd happened to still have an active license}  Avira is working just fine with Sandbox deletion.

Same problem here. I think it started with one of the last two Eset module updates on 18.06.2019 or 25.06.2019.

I don't like Avira because of their aggressive marketing. Kaspersky is not compatible with Sandboxie and Bitdefender has a bad performance and no expert options.

EDIT: Did you restart your system after you disabled Eset compatibility in Sandboxie? It seems to work for me.

EDIT 2: After two days of testing with Eset compatibility disabled, I actually can't reproduce the problem anymore.

I tested it with Firefox 68.0 x64, Internet Explorer 11, the old Palemoon 26.5 x86 with downloaded and moved files and PDF read in the browser and even after Windows 7 x64 hibernation.

Maybe the solution only works with Sandboxie 5.28 on Windows 7 x64.

I will post it if the problem should occur again.

EDIT 3: It occurred for all sandboxes in use when I updated a software outside of Sandboxie (the installer uninstalls the old version first). :-|

EDIT 4: I tested it again with Eset compatibility enabled and then it practically always happens. With compatibility disabled it happens much less. 

Good afternoon, I use Eset Internet Security.
I have tried all the indications that have been commented (Deactivation compatibility, etc ...) but it does not work with any.
I have tried other AV but I do not like them.
I hope it can be solved as soon as possible.

Thank you.

hello! i have the same problem. All solutions provided by Bard doesn't help. I hope that developers will find a solution.

Reinstalled NOD32 for some more testing.

Sadly did not notice any decrease in frequency with removal of ESET compatibility:  {on Win10 1903 18362.239, Sandboxie 5.31.2}

The issue has always been extremely random on this end though.  Sometimes it happens after a single start and termination of a browser following a boot, sometimes it won't occur until a day's end with dozens of repeat closures.  I can also now confirm that this impacts "any software" under Sandboxie, not just Chrome / Palemoon, the reason the occurrence rate is so high with browsers is just due to how often they're launched and closed.

-- For instance, had this happen under VLC Media Player yesterday.  For that matter it happens with LibreOffice, TightVNC, Microsoft Word, several IRC clients.  Just keep starting and closing a program and sooner or later the hive won't close.

** ESET support has informed me that they've added the Sandboxie behavior to their internal list of issues...  They told me that this is not considered a "high-priority" & that very few have reported such, yet also that mixing security-software is not guaranteed to work {e.g, no promises will be made on fixing it}.

Maybe it's because of what Eset last marked as scanned. Run a full scan, maybe the problem will occur less often.

Did you refer Eset Support to this thread? This might help to increase the priority a bit. Unfortunately this is probably not the case.

Edit: I've already checked with ProcessMonitor (also started as admin) what accesses the registry keys HKEY_USERS\Sandbox_, but nothing is found if you exclude the processes of Sandboxie and the software itself. So it can't be ekrn.exe.

Maybe it's because of what Eset last marked as scanned. Run a full scan, maybe the problem will occur less often.

Did you refer Eset Support to this thread? This might help to increase the priority a bit. Unfortunately this is probably not the case.

Edit: I've already checked with ProcessMonitor (also started as admin) what accesses the registry keys HKEY_USERS\Sandbox_, but nothing is found if you exclude the processes of Sandboxie and the software itself. So it can't be ekrn.exe.

tec tec said:

Maybe it's because of what Eset last marked as scanned. Run a full scan, maybe the problem will occur less often.

Worth a shot, perhaps if there's no registry changes made over the course of a session then cached scan results might help.

tec tec said:

Did you refer Eset Support to this thread? This might help to increase the priority a bit. Unfortunately this is probably not the case.

I had not, yet I've now tacked this into the ticket.

tec tec said:

I've already checked with ProcessMonitor (also started as admin) what accesses the registry keys HKEY_USERS\Sandbox_, but nothing is found if you exclude the processes of Sandboxie and the software itself. So it can't be ekrn.exe.

I've not tried Process Monitor yet.  Though Process Explorer, Process Hacker, Lock Hunter, etc, list ekrn as the culprit.  I'd expect that perhaps the method employed for monitoring access is different in Process Monitor.  -- At the very least we know that if NOD32 is uninstalled or real-time protection is disabled, the problem goes away.  {It minimally has to be some form of interaction involving ESET's real-time scanner}

Jerry Atricks -- One of the initial troubleshooting steps that I tried was a Win10 VM as a fresh install of 1903, rather than my feature-upgraded.  That said, DISM and sfc /scannow come back clean (no errors).

The Process Explorer only shows which process was started by which one. It can't show registry calls, or am I missing something?

Since my upgrade of PDFCreator (which has nothing to do with Sandboxie) suddenly prevented all sandboxes that were currently in use from being cleared, Eset must have blocked a registry key that was also used by software outside of Sandboxie.

As an attempt, I nevertheless enter the RegHive file into Eset's scan exceptions: C:\Sandbox\username\*RegHive

tec tec said:

The Process Explorer only shows which process was started by which one. It can't show registry calls, or am I missing something? 

Process Explorer [and Process Hacker] can't list registry-access persay, yet they can list all opened handles by a given process.  Or specifically in this case the file-handle of Sandboxie's mounted hive.  If Sandboxie is completely closed {including the service unloaded}, the only remaining software with open handles for the hive are Windows (system) and ekrn.

I had not tried placing exclusions based on the hive files -- only by application exclusions, I'll have to give that a shot too.

Scan exception: C:\Sandbox\username\*RegHive doesn't help. :-|

Edit: The coming cleaner module 1197 (currently 1195) could be the solution.

forum.eset.com/.../

Awesome!  Glad that this is getting adequate publicity and that ESET is looking into it. (more than I was let on to believe in my ticket and calls!)

Can't wait to switch back off Avira.

ESET Cleaner module 1197 has fixed the issue for me on two 7x64 machines.

Page42 said:

ESET Cleaner module 1197 has fixed the issue for me on two 7x64 machines.

How can I get this "ESET Cleaner module 1197" so that the problem goes away? Will it be downloaded as a virus definitions update by itself or do I downlaod it from somewhere?

I have ESET Antivirus for Business, version 6.something.

Thank you.

I joined this forum this morning just to say thanks for this thread. Once I found this thread it was a simple matter to set the two Win7/x64 machines I use to download pre-release updates. Once ESET Cleaner module 1197 installed and I rebooted, Sandboxie is working normally.

Thanks again to everyone in the thread.

Where did you get it? 

Set your ESET updates to download pre-release updates instead of regular updates. Then go to update screen and click on Update Now.

After that you can check view all modules to make sure you received the update.