Is working in the confectionery industry that uses pork fat considered unlawful, especially if the salary earned from this work will be used to go to Hajj?

Pork and its fat are unanimously forbidden, based on the Almighty's saying: "Say, 'I find not in that which has been revealed to me anything forbidden to an eater who eats it, except that it be a dead animal or blood spilled or the flesh of swine — for indeed, it is defilement'" and "Forbidden to you are carrion, blood, and the flesh of swine."

Therefore, professions that rely on pork fat are impermissible. Immediate repentance is necessary by abandoning this profession, regretting past actions, and resolving not to return to it.

Part of complete repentance is getting rid of ill-gotten gains by spending them on public welfare projects for Muslims or giving them to the poor with the intention of disposing of them. You are only entitled to the original permissible capital, if any; otherwise, you must dispose of all of it, as per the Almighty's saying: "And if you repent, you may have your principal [remaining]; you will not wrong [others], nor will you be wronged."

Hajj is not permissible with money earned from this profession. Instead, you must dispose of it and seek lawful money for Hajj. Otherwise, Hajj is abrogated until you find a means to perform it. It is worth noting that Hajj performed with ill-gotten money is considered valid by the majority of scholars, but you would be sinful for it.