His boss gave him the job of following up on some technical drawings, and he managed to save some money on that
Question

                I work for an engineering company. The boss gave my colleague the job of following up on the preparation of some technical drawings outside the Kingdom, and my colleague agreed with him on the fees that would be paid to the engineers who prepared the drawings. I was not present with my colleague and the boss did not inform me. But when I found out from my colleague, I suggested to him that I could help him and introduce him to some engineers inside the Kingdom for a lower price than outside. In return for what I did of contacting them and setting up appointments and following up with that, my colleague offered me 1500 riyals in return for what I did. But the boss does not know anything about that. When I asked my colleague, “Does the boss know that you have got the job done for a lower price than you told him before?” He said to me, “The boss has nothing to do with it.” He asked him (my colleague) to get the job done in return for a certain amount of money, and he got the job done for a lower amount, and the rest is for him to give to me (the questioner), namely 1500 riyals. Should I accept it or not? I would like to confirm that I am not certain about what happened between them. The boss does not know that I had anything to do with the matter. If there is anything wrong with the way my colleague arranged the matter, does that mean that my taking the money in return for what I did is wrong too? What is my duty towards my colleague if the money he took was haraam? What is my duty towards the boss?.
Praise be to Allah.
      Firstly: 

    The ruling in this case depends on knowing the nature of the 
    agreement that was made between the boss and your colleague. If the 
    agreement between them was that your colleague would look for someone to do 
    these drawings, and he agreed with the boss on the money to be paid for that 
    job, then he was to find someone who would do the job for whatever amount 
    they agreed, then if any of that money is left over, it belongs to him, and 
    if the cost was greater, then he is to pay the extra. This is permissible 
    and there is nothing wrong with you taking the money that your colleague 
    gave you. In this case your colleague is like a contractor who takes on the 
    job, then assigns it to the one who will do it.  

    But you stated that the agreement was based on the idea that 
    he was going to work with the engineers abroad, and that you told your 
    colleague about local engineers. There is nothing wrong with that, so long 
    as the boss does not care who does the work, rather what he cares about is 
    that the work should be done to the required specifications only. 

    But if the boss wanted the work to be done with a specific 
    office or engineer, or he specified that the work should be done outside the 
    Kingdom so that company secrets would not be divulged and cause some 
    problems and the like, then it is essential to fulfil what was agreed, and 
    it is not permissible to go against it. 

    If the agreement between them is that your colleague was just 
    the middleman between the boss and the engineers, and was not to make any 
    profit from this work, then he is acting as the agent of the boss, and the 
    agent does not have the right to make money from the one who appointed him 
    except with his knowledge. In that case, your colleague has to tell the boss 
    what really happened, and that those who are going to do the work are 
    engineers inside the Kingdom, not abroad, and he has to return to him the 
    surplus money. 

    Secondly: 

    If the work that your colleague is doing is haraam, in the 
    way mentioned above, it is not permissible for you to help him, either by 
    telling him about engineers or any other kind of help. Rather you should 
    advise him to fulfil the trust and to avoid consuming that which is not 
    permissible for him. 

    With regard to what you did of phone calls, following up and 
    making appointments, if you did that with the intention of going back to 
    your colleague and asking for the usual payment for such work, then you may 
    do that. But if you did it voluntarily, you do not have the right to ask for 
    anything, but if he gives you something in this case willingly, we do not 
    think that you should take it, unless he has cleared the matter with the 
    boss and he has let him keep the money saved. 

    And Allah knows best.