Is money taken as a "commission" in exchange for my mediation in transferring a sum of money to the company from a person residing abroad permissible or forbidden, knowing that the two parties do not know each other and that communication took place through me?

It is not permissible to take brokerage fees or commissions except with the knowledge of the one who pays them, which in this case is the company. What the questioner took without the company's knowledge is not permissible for her, and she must return it or seek the company's forgiveness for it.