As of this writing it cannot be decompiled.
However there are many scammers out there.
Many of them even show an Mq4 as screenshot , with some code in it...so that it appears they have decompiled.
Hence just ask them to do just one thing.
Ask them to give an ex4 with one of the parameter hidden. For safety you may ask them to make it expire within a day.
Then if you run it, and it works as original it can be assumed it works. ( Never Likely )
Also scammers always demand money in Cryptocurrencies like BTC etc.. so that you cannot complain anywhere.
Hope I have saved you from a scammer, if you happened to read this.