Is working for a software company that requires online transactions and an electronic signature on a non-disclosure agreement, with work and pay shared between an individual contractor and his colleague, permissible or forbidden, and is the shared money lawful?

You erred in taking the test with your colleague because it involved cheating and deception, as the company tests individuals, not teams. If the company does not stipulate that you must perform the work yourself, then there is no harm in sharing the work between you and your friend, and his wage would be due from you. However, if the company stipulates direct performance, then it is not permissible to use someone else, according to the Prophet, peace and blessings be upon him, who said: "Muslims are bound by their conditions." It appears that the company does not authorize the use of others. Therefore, it is not permissible to involve your colleague in the work, and the money you received is in exchange for completed work, and what your colleague receives is due to him from you, not from the company.