I got, that they are randomly generated. What I mean is "random" in case of computer science - is a result of execution of some function, that returns "random" result after long line of mathematical operations
What do you even mean? If the code is meant to produce random results, it will produce random results. Anything less is not truly random. Producing the same result twice should depend entirely on the odds and nothing else. The odds in this case is astronomically low.
So, I`m asking what about if some third party will intervene in a process of generation of an adress (let`s say, some cool-*ss hacker) to generate exact the same adress the same moment (let`s say it`s happening on blockchain.info). Then you send your BTC to this adress, thinking that it`s safe. Will the bad guys get an access to your coins in this case? Sorry if I explaining it horribly, confused in technicalities.
I don't entirely get what you're saying because running an exact copy of blockchain.info's private key generator at the exact same time wouldn't necessarily provide the same result. This will only happen if they use the current timestamp as the
sole random seed, in which case the problem is their method of generation, not Bitcoin's security.
But yeah, as a general rule, if collision does happen, then the two holders would both have access to the coins in them.