Is a certificate obtained through cheating on exams considered void? Is it permissible to work with it? And is the livelihood earned from it lawful?

It is not permissible to obtain a certificate unlawfully, due to the presence of lying, deception, forgery, and fraud therein. The Prophet (peace be upon him) considered bearing false witness and uttering falsehoods among the greatest of major sins. Therefore, forging a certificate is not permissible, and destroying a forged certificate is a correct action, as it is not permissible to use it to obtain a job or complete studies. It is advised to seek employment that does not require what one does not possess, or to strive to obtain a legitimate certificate, and to fear Allah and be patient; for whoever fears Allah, He will provide a way out for him and sustain him from where he does not expect. As for the money that a person who has forged a certificate receives for work, some scholars have withheld judgment on it, while others have said: if the work is permissible and he performs it perfectly, then there is no harm in the remuneration for his work, but it is not permissible to present a forged certificate to obtain the work.