The real trick is to weaponize them in a way that they spread optimally and then disperse them in a way that avoids detection as long as possible. North Korea

The real trick is to weaponize them in a way that they spread optimally and then disperse them in a way that avoids detection as long as possible. North Korea has had bio-weapon development program for a long time and has conducted human experiments with prisoners. They also might do larger scale testing in remote islands. No need to Biosafety level 4 laboratory if the researches are not allowed leave the lab and go home every night. If things go south, you torch the island including the people and start over after few years. It's almost impossible to know how good they are in bio-weapons until they use them.