They aren't competing with FAANG salaries, except maybe for a few outside experts that they might bring in to kick off a program.
They have all the top cybersecurity specialists they could ever need.
https://globalnews.ca/news/5029484/north-korea-malnutrition-...
Number of security researchers isn't a function of population size it is a function of population size * fraction with propensity to show requisite skill * fraction who go to work in the profession.
Shockingly adding millions of more starving people who have never seen a computer doesn't get you many more cybersecurity specialists.
The upper caste from which all their "talent" is drawn is a small fraction of its total population mostly composed of the descendants of the lower class peasants and workers who supported the rise of the current regime. They supported not an establishment of such a system but rather an inversion of the prior order. It's an impoverished field from which little of value grows. To be clear there is nothing inferior about North Koreans by nature it is that the regime wastes the value that it does get.
Einsteins are in theory as apt to be born from the less privileged classes but there is only a 50 50 chance of getting enough food to be healthy let alone a chance at intellectual development.
By your same logic, they would not have any Olympic competitors, let alone medalists.
Most nations educate millions to 10s of millions in order to get their doctors, scientists, software developers, leaders. Someone who educates merely thousands of the kids of new rich kids selected primarily from the ranks of the lowest echelons of society a century OK is poorly positioned to be the best in any field.
Just like with Russia or China, by bribing cybersecurity specialists.