Are ASICs Resistant to Maleware Attacks?

One of the arguments made in favor of relying on ASIC mining hardware to secure the Bitcoin blockchain is that commodity hardware is more prone to a 51% attack as an attacker could easily infect millions of computers through malware attack and use the computer’s resources to execute a 51% attack on the network.

It’s very hard to.. hack into someone’s SHA256d ASICs

Are ASICs really resistant to malware attacks? If so, why?