They did, to some extent, though not to the degree I described.

As an American, I would be more worried about China than Russia though. They makes a lot of our hardware and firmware, giving them plenty of chances to embed killswitches and zero-days. They have possibly the most successful industrial espionage program in the world, giving them the opportunity to find vulns in other systems and embed agents inside critical platforms. They have deeply internalized the concept of fighting where their enemy is weakest not where they are strongest, so they have likely invested in attacking the American military at home rather than on the field.