Question Security with absolute certainty ?

[TheFlash1300]

I have very important files on my laptop , and I want to keep them safe from viruses and ransomware that can encrypt them and steal them from me. I have several back-ups, but I'm still paranoid.

My question, is how to have absolute certainty that my laptop definitely doesn't have viruses? As far as i know, Avast and Windows Defender are the best programs for fighting viruses. I run cheks with both programs, and they always show there are no viruses. However, I don't believe them 100%.

Recently, I accessed a website, but I forgot to enable the ad-blocker, and suddenly, the website opened 11 more links (pages) that redirected me to spam pages containing scams like:

"You win X prize. Send SMS and you will get the prize!"
" WARNING: Your PC is infected. Download this program to remove the virus!"

I know that I don't have to download, run/install any programs in order for the laptop to get viruses. Viruses can be released into the laptop through the browser, by extensions, and infected chance files sent to my browser from a website. This is why I think the websites infected my laptop.

After this accident, I used PowerShell to scan for viruses. It said no integrity threat are found.

If I open PowerShell, and type this:

sfc /scannow

Or:

Repair-WindowsImage -Online -RestoreHealth
sfc /scannow

And, both show everything is fine and there are no problems, dos that guarantee with an absolute certainty that there are really no problems, or it simply means there could be viruses that are too advanced for the PwerShell to detect them, meaning PowerShell is not good enough to detect them, so it says there arent any threats, despite he fact there are?

Also, what files does PowerShell scans - system files, only the files related to Windows 10, or all files on the drive?

 

[USAFRet]

The only way to have "absolute security" is to:

1. Dig a deep hole
2. Put the PC in the hole
3. Fill it with concrete
4. Forget where the hole is

sfc /scannow does not check for viruses.
It checks and possibly fixes corrupt Windows files.

Windows Defender checks for a virus. MalwareBytes checks for malware.

 

[Bob.B]

I have very important files on my laptop , and I want to keep them safe from viruses and ransomware that can encrypt them and steal them from me. I have several back-ups, but I'm still paranoid.

My question, is how to have absolute certainty that my laptop definitely doesn't have viruses? As far as i know, Avast and Windows Defender are the best programs for fighting viruses. I run cheks with both programs, and they always show there are no viruses. However, I don't believe them 100%.

Recently, I accessed a website, but I forgot to enable the ad-blocker, and suddenly, the website opened 11 more links (pages) that redirected me to spam pages containing scams like:

"You win X prize. Send SMS and you will get the prize!"
" WARNING: Your PC is infected. Download this program to remove the virus!"

I know that I don't have to download, run/install any programs in order for the laptop to get viruses. Viruses can be released into the laptop through the browser, by extensions, and infected chance files sent to my browser from a website. This is why I think the websites infected my laptop.

After this accident, I used PowerShell to scan for viruses. It said no integrity threat are found.

If I open PowerShell, and type this:

sfc /scannow

Or:

Repair-WindowsImage -Online -RestoreHealth
sfc /scannow

And, both show everything is fine and there are no problems, dos that guarantee with an absolute certainty that there are really no problems, or it simply means there could be viruses that are too advanced for the PwerShell to detect them, meaning PowerShell is not good enough to detect them, so it says there arent any threats, despite he fact there are?

Also, what files does PowerShell scans - system files, only the files related to Windows 10, or all files on the drive?

Absolute certainty.....turn it off.

If you would like to use the pc keep your backups current and keep your anti-products current.

 

[USAFRet]

And make more use of the squishy thing between your ears.
(meaning...don't click on shady websites)

 

[TheFlash1300]

The only way to have "absolute security" is to:

1. Dig a deep hole
2. Put the PC in the hole
3. Fill it with concrete
4. Forget where the hole is

sfc /scannow does not check for viruses.
It checks and possibly fixes corrupt Windows files.

Windows Defender checks for a virus. MalwareBytes checks for malware.

What is the best way to scan for malicious software? Usually, I use Avast and Windows Defender. If, both, Avast and Windows Defender show there are no threats, does that mean there are really no threats, or does it simply mean the viruses are too advanced, more advanced than the anti-virus tool's definitions, meaning the anti-virus programs are not advanced enough to detect the virus, so they just say there are no viruses, despite the fact there are viruses?

Is there a way to know with certainty if there are viruses or not?

 

[USAFRet]

Win Defender or Avast...One or the other, not both.
Given the ever more intrusive aspects of Avast/AVG...Win Defender wins for me.

No antivirus solution is 100%. There is always the small possibility of a "zero day". Something that has never been seen in the wild before.
But current AV tools work not just on definitions, but also behavior. If it acts like a virus, it is probably a virus, even if it is not yet in the definition table.

 

[Lafong]

Is there a way to know with certainty if there are viruses or not?

No.

You suspected there isn't and you were right.

What's your next move?

 

[dwd999]

I have very important files on my laptop , and I want to keep them safe from viruses and ransomware that can encrypt them and steal them from me. I have several back-ups, but I'm still paranoid.

My question, is how to have absolute certainty that my laptop definitely doesn't have viruses? As far as i know, Avast and Windows Defender are the best programs for fighting viruses. I run cheks with both programs, and they always show there are no viruses. However, I don't believe them 100%.

Recently, I accessed a website, but I forgot to enable the ad-blocker, and suddenly, the website opened 11 more links (pages) that redirected me to spam pages containing scams like:

"You win X prize. Send SMS and you will get the prize!"
" WARNING: Your PC is infected. Download this program to remove the virus!"

I know that I don't have to download, run/install any programs in order for the laptop to get viruses. Viruses can be released into the laptop through the browser, by extensions, and infected chance files sent to my browser from a website. This is why I think the websites infected my laptop.

After this accident, I used PowerShell to scan for viruses. It said no integrity threat are found.

If I open PowerShell, and type this:

sfc /scannow

Or:

Repair-WindowsImage -Online -RestoreHealth
sfc /scannow

And, both show everything is fine and there are no problems, dos that guarantee with an absolute certainty that there are really no problems, or it simply means there could be viruses that are too advanced for the PwerShell to detect them, meaning PowerShell is not good enough to detect them, so it says there arent any threats, despite he fact there are?

Also, what files does PowerShell scans - system files, only the files related to Windows 10, or all files on the drive?

If your files are that important you should not be using that computer to access the internet or any other computer. Buy an inexpensive computer just for internet access. They like to call that Air Gap.

 

[TheFlash1300]

If your files are that important you should not be using that computer to access the internet or any other computer. Buy an inexpensive computer just for internet access. They like to call that Air Gap.

Thanks for recommending me Air Gap. I will try it.

 

[mdd1963]

Whatever website you visited that hit you with all the spam is clearly not a safe website....

You'd be advised to have anything important backed up on some sort of drive not connected to your laptop.(if ever hit with ransomware, naturally said ransomware goes after all devices connected to laptop and/or even network shares if it can get to them.

If you have an external USB drive of sufficient size, you could take a backup image of your entire laptop as it is/was at the time of the backup with either rescuezilla or Macrium Reflect (free version). WIth spinning drives as a source of destination, this takes about an hour per 150 GB of data/utilized space, but, hopefully, you'd never need to restore. (With one of my laptops several years ago, I imaged to an external drive, replaced the functioning spinning OS drive with an SSD, and, restored the image just to practice/verify the imaging/restoration process was sound and would work if ever needed. )

As long as your actual needed files are safely stored somewhere in a few places, that's what counts, as an OS can be installed in just 3-4 minutes these days, making the ability to restore everything nice and convenient, but, not quite as critical as it once seemed...

 

[USAFRet]

I have very important files on my laptop

So does everyone else on the planet.

What is your backup situation at home?

What is your backup situation at home? And if you don't do that, why not? Every single day, I read multiple threads here of "How do I get my stuff back?" or "That drive had 5 years of photos of my kids!!" Be it a dead drive, dropped phone, virus, accidental deletion, formatting the wrong...

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