TP-Link routers have been infected by a botnet to spread malware

Anyone know the firmware version I should hope to see on mine (I have this exact AX21 router, just purchased like five months ago, FML)? It says no updates. 1.1.1 Build 20240822 Rel. 44461

[EDIT] Also, if suspect infected... discard? Manually flash firmware from USB (if possible, I haven't checked)?

This seems to be less of an issue if the web management interface is not exposed on the Internet for example LAN-facing or exposed WAN-side but not reachable due to CGNAT.

Is this a hardware, or software problem? What if I've got a TP-Link router running OpenWrt? TP-Link routers are very easy to get OpenWrt on. I've done that many times.