Microsoft Defender for Linux !

Microsoft Defender is available (free) for Ubuntu !
# apt show mdatp
Package: mdatp
Version: 101.25042.0003
Priority: optional
Section: devel
Maintainer: Microsoft Defender Group <mdatplinuxpackages@microsoft.com>
Installed-Size: 530 MB
Depends: libc6 (>= 2.23)
Download-Size: 157 MB
APT-Sources: https://packages.microsoft.com/ubuntu/25.04/prod plucky/main amd64 Packages
Description: Microsoft Defender (Production)
Microsoft Defender is a complete endpoint
security solution. It delivers preventative protection, post-breach
detection, automated investigation, and response.

It takes about half a gig of disk (roughly the same as ClamAV IIRC):
Download size: 157 MB
Space needed: 530 MB