@dadmin To our best knowledge, the pcWRT router is not affected. Per Ars report, there’s no evidence of infection for similar firmware such as Tomato, Merlin and DD-WRT either.
Even though the cause of infection is not clear, the presumption is that it is exploiting known flaws, e.g., unpatched firmware, default passwords, remote admin interface, etc. The pcWRT router does not have a default password, and it doesn’t open a server port on the router for remote admin. If you do enable remote admin for pcWRT, the communication between the router and pcwrt.com is encrypted with TLS. Whereas some major brands does remote admin via plain HTTP.