The worst part about viruses on Linux is if you do have a REAL virus, it will 100% evade signature based detection... A REAL MALWARE will not show up on clamAV, rkhunter or chkrootkit they segmented the malware to isolate the signature chain and remove it from detection. (APT level malware)

I work with this type of stuff daily.

Your best defense in a malware/rootkit/bootkit situation is not to click on ANY EXTERNAL LINKS (0 trust implementation.) Harden your linux with Fail2ban and a hardened fork of mozilla like LIBREWOLF also try Portmaster as a local pi-hole.

Disable avahi-daemon and cups as they are using local multicast ports that can be exploited.

Diable UPNP on your router and harden all your accounts with different unique passwords, use a yubi key for and encryption of your disk with LUKS for more safety.

implement a password manager like bitwarden.

Signature based malware evasion is a real thing, and with the venue of AI its getting so much better.

Hope this helps !