I'll give you just a hint, because figuring out the algorithms and logic is fun :)
Cached user resource amount and buildings level can be requested from api.drugwars.io, you have to combine that information with production rate of each building calculated at current level and elapsed time to now. After those steps you can estimated resources level at any point of time. No "hack" is needed you have just read the game JS, currently the code is not obfuscated so it is very easy.
RE: DrugWars: Custom JSON Operations