Routers drop unsolicited incoming packets so the attack stops there. WiFi however is too easy to interfere with and all it takes is a car with a noisy electrical system to drive by.
But there are folk that install cracked OSes and software and the attack is from within. Think of that as they invited the attack.
Several nights ago, wireless and wired networking in my house became very unstable, booting devices off, rebooting, and experiencing outages. By the next morning, my modem was completely inoperable, only signalling it had power, even after several reboots.
Modem resumed proper operation after being replaced (LED indicators & logs signalling no issues), but router issues persisted even after several restorations to factory defaults. I believe WAN and DCHP issues are the root of the router's problems, but a router not previously connected to the network works without issue while I order a replacement (router is <6 months old).
After replacing both modem and router, noticed my PC continued to have connection issues, with windows troubleshooter unable to resolve Ethernet adapter issues. Upon some investigation, I discovered my Ethernet drivers had all been disabled, and other networking tools uninstalled. Upon reinstallation & reboot, it resumed normal function as well. I ran a scan with malwarebytes and it turned up quite a hits, but I believe they were false positives (Bitcoin miners from reputable sources).
I find it odd that every device physically connected to my network was simultaneously crippled, only being fixed by replacement devices, and uninstallation of software on my PC makes me suspicious of a full network attack...