Firstly this question concerns cryptocurrency, which a big warning sign for scams any time it is mentioned, and a major tool of criminals.
Secondly your friend should consider whether he knows anything about the complex world of cryptocurrency. If he checks, he will soon realise that he does not, which is another big warning sign.
Then, there's the issue that converting cryptocurrency to cash is not a job. It is something that can be done automatically, or very simply and casually by an exchange such as Netcoins by the person who owns the crypto. Always check if you are actually doing a real job. So if the thing you are doing is not a real job, then what are you doing there? Being used as a tool by a criminal, that's what. In other cases, you may think you are doing a job, but you are actually there to eventually give your money to the criminal by some process you do not realise.
Also, in checking whether the job is real, another basic step is to properly check whether the company is real. Even online companies should be real before you deal with them, let alone take 'jobs' with them. In this case, it is guaranteed that a reasonable search will show that this is a totally non-existent company. There is no legal employer, there is just a shadowy person sending the cryptocurrency. Your company you work for not actually being real is obviously a problem.
There are no people working for this fake company, doing 'marketing work' or any other work. Bad people will lie to you.
Your friend is being used by criminals to convert cryptocurrency because the criminals really don't want to do it themselves. That's one way they get caught.
Always, the criminals don't want to do the conversion themselves, because the cryptocurrency they are sending is stolen money, so he would rather your friend commit the offence of converting the stolen crypto to cash, so it is your friend that will get caught.
They probably pay your friend OK for what he does, but no payment is worth it for committing a criminal offence for other people that nobody will even be able to find later on.
What your friend is doing is 'money-laundering' (cleaning 'dirty' money for thieves so that they can get it back and spend it), and it's a serious felony. When it is found out, the only one the police will ever find is your friend, so they really won't want to let him go.
Your friend is called the 'money mule' in this scheme. Money mules often go to prison for money laundering.
They cannot find the thieves most times, because the crypto side is very hard to trace. And the thieves have taken all the steps to be anonymous. No name or contact your friend thinks he knows is real, any phone number will be a burner phone (or nowadays a VOIP number).
Your friend will find it hard to plead ignorance, because the job makes no sense, it is so clearly not with a real company (employment paperwork? tax codes? company registration? company business account? real office address? if he found the real company on Google Street View, and have the company registration, did he call to check the person actually works there?). Your friend would not only be the one committing the offence, he is getting paid for it, so he is part of the criminal gang, even if he says he didn't know.
If the pay is poor, he is risking going to prison for little money. If the pay is decent, he has even more chance of going to prison, because the court will assume that a reasonable person knows that they are doing something wrong, if they are being paid to do something strange. Something strange to do with other people's money!
It doesn't matter legally that your friend didn't steal the cryptocurrency, it doesn't matter legally that your friend was not aware that what he was doing is an offence. Ignorance of the law is no defence, sadly. The clear signs that nothing here is real or how business is done, will work strongly against your friend in court when he tries to say he fell into a trap and plead innocence and say he couldn't have known.
I suspect your friend knows there is something quite wrong here, but he is taking the attitude "How bad can it be?". The answer is obviously "very bad".
In the UK for example, laundering and distributing criminal money attracts a sentence of up to 14 years. Even with a shorter sentence, or even a big fine, a conviction can affect your friend's ability to have a bank account, borrow money, and work in certain sectors, like finance and anything related to law and being trustworthy.
Your friend should run very far away from this. Like yesterday.