I think I've got malware on my laptop. You see, I got suspicious disc activity
after accessing a dodgey website.

So I'm going to run rkhunter on the laptop from a live knoppix USB stick.

My linux system is on partition /dev/sda6. Presumably I need to actually MOUNT
sda6 in order to run rkhunter on it (or am I wrong). But if I mount it, does
this allow the malware to become active and do nasty things?

I'm only just starting to learn about malware scanners, and was proposing to run
the following on the laptop: rkhunter, chkrootkit, and clamtk or clamav. Will
running all 3 programs be sufficient in searching for malware?

I acquired the malware while running linux on sda6, but do I need to check for
this malware on the other partitions too (sda1, sda2, and sda3 are for Windows,
and sda5 is linux swap)?

Is rkhunter better than chkrootkit or vice versa?

Many thanks.

Best way is to use a CD not a usb stick as usb can be written to unless it has a write protect switch.
I would check the entire disk to be on the safe side.

Personally, I prefer rkhunter and is what I use on my FreeBSD boxen.

Running both on a Debian box, chkrootkit seemed to give a lot of false positives.

Try malwarebytes, for Windows.

I agree with the live cd or a usb without persistance sort of boot. Have no other drive connected.

The problem with trying to fix a problem is that you can't always be sure you have it fixed. I'd consider the data's value versus the systems or lans value.

If this is an OS drive then just reload from known good sources.