Outlook Attachment issues

[katycomputersystems 1]

Tuesday afternoon, several of our end-users are reporting issues with Outlook attachment handling when ESET Endpoint Security v 10.0.2045.0 is installed. Outlook locks up when attempting to save, preview or view attachments. We have tested PDF & XLSX attachments, both file types have the same issue.

We have tried many things, the only certain resolution is uninstalling ESET Endpoint Security.

The affected computers are running these versions of office.
Microsoft 365 / Outlook v2301 16.0.16026.20238
Microsoft 365 / Outlook v2303 16.0.16227.20280
Microsoft 365 Apps for business / Outlook v2304 16.0.16327.20214

Some users are on W10 others are on W11

What settings can we change to make this a better situation for our end-users.

[Marcos 5,074]

Please raise a support ticket. We've seen issues like this when Windows didn't turn off Windows Defender and it was running concurrently wih ESET.

[Michelle911 0]

I was having the same issue and found that Windows Defender was not turning off with Eset installed. Once I turned off Windows Defender through group policy (or local security policy in a workgroup) to I have no more issues.

[perbauer 0]

On 4/27/2023 at 10:30 PM, Marcos said:

... turn off Windows Defender ...

Is it enough to turn off Real-time Protection in Windows Defender under Virus & Threat Pro.? See image

[Aaron Haydon 0]

@katycomputersystems

We are only having the issue with Lenovo Laptops at the moment is that the case for yourselves?

[Marcos 5,074]

On 5/11/2023 at 8:34 AM, perbauer said:

Is it enough to turn off Real-time Protection in Windows Defender under Virus & Threat Pro.? See image

That should be enough I assume.

[perbauer 0]

Just now, Marcos said:

That should be enough I assume.

I just tested this yesterday and sadly it was not enough to only disable Real-time Protection. I ended up disabling all of Defender. 

[perbauer 0]

11 hours ago, Aaron Haydon said:

@katycomputersystems

We are only having the issue with Lenovo Laptops at the moment is that the case for yourselves?

Nope, on HP here. 

[Aaron Haydon 0]

We have used this workaround to solve the issue 

New-ItemProperty -Path “HKLM:\SOFTWARE\Policies\Microsoft\Windows Defender” -Name DisableAntiSpyware -Value 1 -PropertyType DWORD -Force

Hope this helps

[MHDigHip 0]

I am having a similar issue with v10.0.2045.0 causing a 10-15 second slowdown when previewing or opening any attachments in Outlook 365.  Disabling real time scanning or pausing all protection is the only way to alleviate the issue.  Disabling client email integration does not help, nor does disabling Defender via PS command or GPO, full reinstall of Office/ESET, different Outlook profiles or safe mode.  I eventually landed on disabling the real time scanning of outlook.exe, while still leaving all email client integration enabled, and attachments load with speed now.

The laptop in question is a Lenovo Thinkbook.

Any insight is appreciated, thanks!

[Marcos 5,074]

28 minutes ago, MHDigHip said:

I am having a similar issue with v10.0.2045.0 causing a 10-15 second slowdown when previewing or opening any attachments in Outlook 365.  Disabling real time scanning or pausing all protection is the only way to alleviate the issue.  Disabling client email integration does not help, nor does disabling Defender via PS command or GPO, full reinstall of Office/ESET, different Outlook profiles or safe mode.  I eventually landed on disabling the real time scanning of outlook.exe, while still leaving all email client integration enabled, and attachments load with speed now.

Please carry on as follows:

1. Disable Protected service in the advanced HIPS setup
2. Reboot the machine
3. Run Procmon and start logging
4. Launch MS Outlook and reproduce the issue
5. Stop logging
6. Save the Procmon log unfiltered and compress it
7. Collect logs with ESET Log Collector and upload the generated archive here along with the compressed Procmon log.
8. Re-enable Protected service and reboot the machine.