Boot scan

Avast Free Antivirus / Premium Security
1

I ran a full scan the other day and after I got a lot of results saying I have corrupted archives I decided to run a boot scan today, it showed fewer corrupted archives but I noticed that the number of checked files is far lower…

For full scan I got: 2135126 files

For boot scan of all local disks I get: 1639750 files

Why does the boot scan seem to check fewer files and which does it skip?

2

Because there are fewer files to check as not everything is loaded when the boot scan runs.
Next to that it only checks certain locations/files and not the entire drive(s).

3

How can I make it check all the files on the drive? When I pick all local disks doesn’t scan everything on them including for example picture folders since that’s where I got some error from the full scan…

4

You can’t.
It simply checks all the important places where malware can reside.

5

I see, can you tell me how the full scan says a JPG file is a corrupted archive when it’s clearly a picture? I have several photos from a folder detected as corrupted archive files…

6

jpg is a compressed image, so you could call it a archive.

Don’t worry about the message.

7

Sorry I meant PNG…

Here’s what I get:

D:\My Pictures\Pictures\For Me\CSKJu.png|> [E] ARJ архива е повреден. (42120)

It says the archive is corrupted, is it normal? Can a virus have infected it?

8

Portable Network Graphics (PNG /ˈpɪŋ/) is a raster graphics file format that supports lossless data compression

As I said, don’t worry about it.

9

I see, thanks.

Just another quick question, if the boot scan doesn’t scan everything how is it more secure than the full system one? I mean if it skips files what if there’s a virus there?

10
if the boot scan doesn't scan everything how is it more secure than the full system one?
It is not, Boot scan is to be used if you have a infection that is difficult to remove
I mean if it skips files what if there's a virus there?
avast have realtime protection, meaning evrything that goes on in your computer when on is scanned/monitored in realtime so any files not scanned by on demand scan will be scanned when whatever in your computer access/use those files
11

So I can be sure there is no infection even if I get so many corrupted archive errors with the scan?

12

corrupted archive errors usually mean they are archives avast will not unpack and scan

So I can be sure there is no infection
Nothing in the world of computers is 100%

You may run Malwarebytes or a online scan like TrendMicro house call if you want a extra check

13

Additionally, a boot scan runs when Windows is not booted, active, or running.

So there would be fewer files to scan as windows is (asleep) inactive.

Additional files scanned would be those running or active when Windows is running and live.

What is an archive file?: https://duckduckgo.com/?q=what+is+an+archive+file%3F&t=ffab&atb=v23&ia=web

What is a corrupted archive file?: https://duckduckgo.com/?q=what+is+a+corrupted+archive+file%3F&t=ffab&atb=v23&ia=videos

As you can see other reasons for corruption than infections, such as password protection.

14

Can they hide viruses?

I don’t see PNG as an archive file in the links you provided…

Should the boot scan process folders with pics and game folders since that is where I get the errors?

15

Here you go: https://www.lifewire.com/png-file-2622803

A definition of an archive file involves some sort of compression.

https://duckduckgo.com/?q=are+.png+files+archive+files%3F&t=ffab&atb=v23&ia=web

[EDIT:] Boot scan scans all files on your hard drive, including your Pictures folder.

[EDIT2:] If curious about detection, upload one of your .png files here and post url link in your next reply: https://www.virustotal.com/