Is it possible for old malware to evade detection by current antivirus programs?

kaisernatron

Are all files from several years ago safe just because they were cleared by antivirus apps with properly updated databases like Malwarebytes? If not, how is that possible? Is there a point of antivirus at all?

NoahRaketic

kaisernatron No, there is very little point to antivirus, especially on Android. You should use apps from trustworthy developers that target recent SDKs.

If you want to understand why trying to enumerate badness is a bad practice:
https://ranum.com/security/computer_security/editorials/dumb/

Johnnyloans

kaisernatron Are all files from several years ago safe just because they were cleared by antivirus apps with properly updated databases like Malwarebytes? If not, how is that possible?

Right now, I could create a new windows virus and scan it with my antivirus and it says it is clean. You might need updates to catch new malware. Antivirus is mainly a windows thing.

Antivirus is a scam on phones because apps are not allowed to access other apps or the operating system. (They can't scan anything)

kaisernatron Is there a point of antivirus at all?

Don't pay for antivirus. Use whatever is built into the OS. Microsoft's defender will scan for viruses.

Stay updated. Don't download sketchy stuff.

kaisernatron

NoahRaketic

Choosing to enumerate only goodness means that you won't be able to detect if it turns bad, for example when a developer is hacked, goes rogue, or has been planning to exploit the trust of users all along

https://en.wikipedia.org/wiki/XZ_Utils_backdoor

But my question was more... is malware just something that executes code and are all .exe files are potentially unsafe even if a reputable antivirus had cleared them?

NoahRaketic

kaisernatron Choosing to enumerate only goodness means that you won't be able to detect if it turns bad, for example when a developer is hacked, goes rogue, or has been planning to exploit the trust of users all along

Enumerating badness is much weaker against the problem of supply chain attacks.

kaisernatron https://en.wikipedia.org/wiki/XZ_Utils_backdoor

I'm aware of this. And no, antivirus software would not have caught this.

kaisernatron are all .exe files are potentially unsafe even if a reputable antivirus had cleared them?

Yes.

Novalissoide

kaisernatron is malware just something that executes code

No, there's social engineering schemes, hacking humans don't always need executing code in a classic sense.

kaisernatron are all .exe files are potentially unsafe even if a reputable antivirus had cleared them?

Yes.

kaisernatron

Novalissoide I'm referring to installed malware specifically, not all forms of hacking

Yes

Thanks

kaisernatron

Johnnyloans It's that easy to create new, undetectable malware? Also just to clarify I'm mainly concerned about my computer (not my phone)

Johnnyloans

kaisernatron It's that easy to create new, undetectable malware?

It's not easy, no.
Very few people in the entire world could do it.

Apparently it does happen because windows downloads more malware data for the antivirus.

kaisernatron

Johnnyloans Apparently it does happen because windows downloads more malware data for the antivirus.

Are you trying to say that Windows has a better database or that it downloads actual malware? But why would that affect people's ability to create new, undetectable malware?

Johnnyloans

kaisernatron

I am saying that Windows downloads updates for its antivirus so it can work better.