Avast detects new viruses after analysis and deletion

Avast Free Antivirus / Premium Security
1

Hello everyone, I’m new here, my name is Alexandre. I will need your advice or solutions.

The problem is simple, I have an internal hard drive that I never use. I recently wanted to check to see if everything was fine virus level. Here is what I did.

  • I do a complete disk scan, Avast finds 10 viruses.
  • I delete them by hand then windows trash
  • Then I redo an analysis, Avast does not detect these viruses but detects 4 new ones.
  • Why did not he immediately detect the 14 viruses?

Thank you for your enlightenment because I am afraid of being infected by a virus that is spread after elimination.

Sorry for my bad english :stuck_out_tongue:

Alexandre

2

since you dont give any info, impossible to answer

3

What info do you need?

My last scan detected 2 new viruses again :

  • WMA:Wimad [Susp]
  • Win32:WrongInf-G [Susp]

And 9 warnings :

  • Decompression bomb

When I delete them, and I redo an analysis it will then detect new ones…

4
  • Decompression Bomb, a file that is highly compressed, which could be very large when decompressed. This used to be a tactic long ago to swamp the system. This doesn’t mean that they are suspect or infected, just files that avast isn’t going to scan and shouldn’t require any action by you.

These highly compressed files are generally ‘archive’ files which are inert, don’t present an immediate risk until they are unpacked. When unpacked then the on-access scanner would then scan the content.

5
- WMA:Wimad [Susp] - Win32:WrongInf-G [Susp]
[susp] = Suspicious
And 9 warnings : - Decompression bomb
As David explained, just a highly compressed file(s) that avast will not unpack and scan

did you run same scan type both times? … what type
where are the detected files located? … full file path

6

Ok for Decompression Bomb,

For the scan :
Right click on the drive F and click on “Analyze” with Avast

For the path of the 2 viruses :
F:\Musiques (téléchargées et CD)\Musiques téléchargées\Break My Heart.mp3
F:\Creativity Concept\Ressources CC(RPGM VX) Res\Party Changer\Game.exe

Thanks guys

7
F:\Musiques (téléchargées et CD)\Musiques téléchargées\Break My Heart.mp3 F:\Creativity Concept\Ressources CC\(RPGM VX) Res\Party Changer\Game.exe
Upload and test file(s) at www.virustotal.com

post links to scan result here

8

First virus : https://www.virustotal.com/#/file/13d7cc59e17eba01c7913b679e6b4d3077b24b57483c5d80d384a18f9dcdc68e/detection
Second virus : https://www.virustotal.com/#/file/ebea96a5054717b334e1ec4b6378427bbc7ddaddea9d8ad1b9e9241e05db26e1/detection

This ? :slight_smile:

9

I would guess avast did not have signature for it or files was checked against avast cloud when you run first scan. avast recive stream updates evry 5-15 minutes

If you click those links tomorrow and then on the blue button at top right and select rescan
If detection rate goes up i guess detection is correct …

10

In short, if I understood everything well. Avast receives automatic updates and can therefore detect new viruses that was not detected before?

Thank you :slight_smile:

11

Little UP :slight_smile:

12

Confirmed.

13

https://www.avast.com/nextgen

https://blog.avast.com/the-5-vs-of-big-data-for-machine-learning

https://press.avast.com/avast-builds-threat-detection-based-on-machine-learning-to-protect-users-from-zero-day-attacks-malware-and-privacy-threats

https://blog.avast.com/fighting-new-wave-cybercrime-next-gen-cybersecurity

https://press.avast.com/avast-software-streaming-updates-for-all-with-the-newa-avast-7

14

Thank you very much! you have been a great help to me. Happy Holidays.

Alexandre