Do I need to be online to perform anti-malware scans or backups?

In this excerpt from
Answercast #99 I look at why a computer may need to be online when
performing virus scans and backup.

Internet connection for anti-malware scans

That's actually an interesting question. It's interesting in the sense that
the answer's actually both yes and no.

Here's what's important - your anti-malware tools (which I hope includes
both anti-virus and anti-spyware), they need to be online at some point. They
need to be online so that they can receive the updates they need to be current
and stay on top of all the most recently released malware.

They don't necessarily have to be online during the scan as long as they
were able to get their updated database. As long as they've got the updated
database, once that's in place, then the computer can be offline and it can
scan all you want. It really shouldn't be an issue.

Updating the malware database

But, the problem of course is understanding when those two separate steps
happen. Some anti-virus tools will actually do them both at the same time when
they start their regularly scheduled scan. They start by connecting to the
remote site and getting the database download before they do the scan.

If those two steps can't be separated, then ultimately you really need to
leave the computer connected to the internet in order for the anti-malware scan
to run. Not for the scan for itself to run but to make sure that it's running
with the most current information possible.

Performing a backup

Now, as far as the backup is concerned, it doesn't matter. It doesn't have
to be connected to backup if you're backing up to an external drive.

If you're backing up to an online service, well obviously, you need to be
online - but if you're backing up to an external drive or to some other place
on your local network, then it doesn't really matter whether you're connected
to the internet or not.

Once again, however, the backup software itself might like to check to see
if there are new versions every so often.

For example, in my case, I run Macrium Reflect and I run it automatically
every night. It does its thing. Yes, I'm connected to the internet but that's
neither here nor there. What is important is that every once and awhile I
should manually run Macrium Reflect. I just need to bring it up. That's when it
does its new version check; that's when it tells me, "Hey, there's a new
version of the software available. Do you want to download it and install it?"
And I do.

But to actually perform the backup? No. No internet is required.

(Transcript lightly edited for readability.)