[SOLVED] Avast blocking legit facebook messages, and images

[REDACTED]

Program version is 11.1.2245 with latest definitions
Operating System is Windows 10 Home (1511) with all updates installed
Browser is Google Chrome, and is also up to date

This just started happening a couple of days ago. When I use the desktop Messenger app, facebook messages appear as normal, but if I open the facebook website, half the images in my news feed, timeline, and groups are broken, and images, or voice memos (voice messages) in facebook messages are always blocked as threats. I know these messages are legit, because they are JPG, PNG, or GIF files, and the URLs for the voice messages show as MP4s. They have all also been sent by people I know, and the blocking started happening during one of my conversations where voice memos were in use.

Since this started happening, i can't listen to any voice messages sent from people I know, and facebook is pretty well broken.

[Pondus]

I know these messages are legit, because they are JPG, PNG, or GIF files,

What does that have to do with being legit / not infected ?

and images, or voice memos (voice messages) in facebook messages are always blocked as threats.

What type of threat does avast say is detected?

[Eddy]

Any file can be called anything and have any extension.
The filename/extension says nothing about being it legitimate or infected or not.

mp4 is Video+Audio.

[REDACTED]

Sorry. When I wrote that, it didn't occur to me that all files can be infected.

When I click on details in the threat popup, it gives me part of the URL, and threat type is URL:Mal

[Pondus]

URL:Mal means URL or IP is blacklisted for whatever reason, it does not have to be infected

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breaking facebook might be a deal breaker, because i use it a lot as a primary method of communication with my family. So the question is, whether there is a way to get Avast to stop blocking these, without turning off the web shield?

EDIT: Per the topic linked below, the problem has been resolved by disabling the HTTPS scanning feature of the web shield. This also resolved issues with some other websites/services having troubles, or being blocked.
https://forum.avast.com/index.php?topic=165244.0

[Eddy]

The SSL/TLS scanning issue has been solved several avast versions ago.
Strange that you do have to disable it.
Especially since no-one else has this issue with the current version.

I suggest you perform a clean installation of avast.

[bob3160]

If you have Avast Online Security enabled, be sure that you aren't blocking
Social Network by default:

[REDACTED]

@bob3160 - Avast Online Security is enabled, and the settings are identical to those in your screenshot, so that shouldn't be the problem.

@Eddy - I will try a clean uninstall/reinstall of Avast sometime in the next day or two, when I get a chance. I will update this thread with the results.

[bob3160]

It looks to me like you are concentrating on Avast when non of us have that problem with Facebook and we are all using Avast.
I suggest you start looking at other blockers that are probably the cause of your problem.

[REDACTED]

I'm focusing on Avast, because Avast sees simple images, and facebook voice memos sent from a smartphone as threats, actively blocking them. Disabling the web shield in Avast, and more specifically the HTTPS scanner that is part of the web shield made the problem go away. This makes Avast the logical item to begin troubleshooting steps. If a clean uninstall, and reinstall resolves the problem, then that still means that the problem was caused specifically by Avast, whether it be by way of a botched update, or even a crash gone wrong. If this process doesn't resolve the problem, then I will begin looking at other potential causes.

You should know by now that troubleshooting issues is a step by step process. Just because I'm investigating Avast as a potential (and most likely) cause of the issue today doesn't mean I won't be looking at my browser, or operating system, or even a virus that Avast may have previously missed as a potential cause tomorrow.

[DavidR]

@  jasoncollege24
You say:

I'm focusing on Avast, because Avast sees simple images, and facebook voice memos sent from a smartphone as threats, actively blocking them.

And later:

<snip>
When I click on details in the threat popup, it gives me part of the URL, and threat type is URL:Mal

The URL:MAL is an indication that the domain or IP address is blocked as mentioned.
Please do this test, enable https scanning again - when it happens again can you capture a screenshot of the alert as this can help us in trying to pin down what is going on.

If you can provide the URLs for some of these links you are trying to connect to and someone can try to analyse that link. When giving examples please ensure the link isn't active, change the http or https to hXXp or hXXps to avoid accidental exposure.

If there is any conflict, remove one element, no conflict, but that doesn't confirm what is the true problem.

[REDACTED]

There is no need. As originally suggested by Eddy, a clean uninstall, and reinstall of Avast resolved the problem. The HTTPS scanner is running, and these messages do not get flagged as threats.

This tells me that something in the previous Avast install had gotten corrupted, or botched in some way. Avast was clearly the cause of the problem. Thanks Eddy!

[Eddy]

You're welcome.

By the way, have you seen my Gremlin ?

[REDACTED]

Yep! I kicked him out about half an hour ago.  You can have him back!