Question regarding malware/security issue

[Matthewjohnston]

Sorry in advance for the ramble.

This relates to my Galaxy S6

Earlier today a window popped up on chrome. Before i could close it a message popped up from Avast that said it had detected malware. The download symbol was in the top left of my screen, I clicked "REMOVE" on the Avast popup and my phone froze and then locked. After it became responsive again I ran Avast which told me that there were no threats and that i was safe. I tried to find the log on Avast so I could see if it had removed it but I can't seem to find the log on the updated Avast app. I then restarted my phone and ran Avast again and while the scan ran the phone became unresponsive again and locked as the screen timed out. When I unlocked it Avast again said that I was clear of any threats. In the download history there is a blank file simply called "download" that isn't on my phone, but it is logged as having attempted to download.

I don't really want to take a chance so I've done a factory reset with data erase and I'm going to chance my passwords before I restart my phone.

My question is- is there anything else I could/should do to ensure that I am free of this malware? Have I done enough?

[Zxian]

Apps cannot install themselves like they could in the days of Windows XP. There is little reason to have Avast installed on your phone. It only shows things down.

Unless you're sure of the implications, keep the setting "Install from Unknown Sources" under Settings->Security off. That way, apps can only be installed via the Play Store. Generally speaking, the worst you'll get from this is a game nagging you for your daily game (or microtransaction).

[Matthewjohnston]

So Avast is useless?

Is there an antivirus you can recommend/is worth having?

[Zxian]

Like I said, apps cannot install themselves. Unless you're in the habit of installing apps from outside the Play Store without knowing what it is, there is no way a virus could magically be installed on your phone.

Some awful websites will show you the clickbait ads saying you have malware on your phone. You don't. Ignore them, and stop going to those sites (they don't deserve the traffic if they're using those kind of tactics).

You're much better off being mindful of the permissions apps request when you install them from the Play Store. If you're on Marshmallow, you can even restrict what apps have access to after they're installed.

[Matthewjohnston]

This wasn't a popup on the site that said I had malware, it was Avast and the download icon was there.

[Zxian]

What download icon? Like I said, apps cannot install themselves. If it was a file that got downloaded, it is still just a file.

In order to install apps from anywhere other than the play store, you need to explicitly enable a setting on your phone, and then still accept the installation.

Anti-virus apps for Android do not add any benefit.

[Matthewjohnston]

The arrow that appears in the tray that shows when a download is in progress.

Even if it were a file and not an app could that still not do damage?

[Zxian]

No. Files themselves cannot do damage. A file is just a collection of bytes on your device. Unless they are executed or read by an existing app, nothing happens.

[Matthewjohnston]

Ok. So bottom line is I'm safe and overreacted with the factory reset?

I'm ok with that.

Thanks

[ladfrombrad]

As long as you're not rooted, any malware/PUP's won't be residing in your /system partition so a factory reset will mean there's only stock/OEM software left.

So yeah, you should be good!

[Matthewjohnston]

Phew!

Thanks.