Hit by Trojan.FakeAlert, is the danger over?

Avast Free Antivirus / Premium Security
1

I am a bit worried after being hit by some sort of virus.

My laptop was suddenly and aggressively displaying different kinds of virus alerts and popups, and they all looked fake to me. I did not click on anything, but tried to kill Firefox using the task manager. When this failed, I shut down the laptop using the power off button.

After a reboot, I scanned the laptop with MBAM. It found one threat:

Trojan.FakeAlert
C:\Users\Username\AppData\Local\Temp\qn2XyW8p.exe.part

I then did a search with Avast, which found the same threat. I removed it using MBAM.

There’s no particular reason why I used MBAM before Avast, other than the fact that I wondered why Avast hadn’t blocked it in the first place.

Here are some questions I would appreciate your input on:

  1. After removing the file with MBAM and getting clean scans from Avast, Windows Defender as well as MBAM, can I consider the laptop safe to use again?

  2. Why didn’t Avast react in the first place?

  3. This happened while I was connected to the web through a VPN, but that shouldn’t affect how Avast works, should it?

Thank you for your help.

2

No antivirus is 100%…You always need something to give additional protection apart from avast…

did avast detect the file on a manual scan??

3
2. Why didn't Avast react in the first place?
maybe it arrived before avast had signature for it?
4

Yes.

I did the manual scan under an hour after the problem occurred, so I don’t know if that would be the case. As a matter of fact, I believe my MBAM database was rather out of date, so that would suggest to me that the virus has been known for a while.

5

Provided all scans are clean, including an Avast boot-time scan, would you consider everything to be OK based on what I describe?

From what I understand, the point of the virus is to scare users into installing software that requires payments, or something along those lines. Could such software actually be installed without the user being aware of it? Would the user not have to approve the installation prompt from Windows 7?