In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
If you have repented to Allah and you give some money in charity, then there is nothing wrong with you remaining in this post, so long as you are qualified for it.
In responding to your question, the Fatwa Center at Islam Q and A, states:
Is bribery permissible?
There is no doubt that paying a bribe in order to get a job is haram both for the one who pays the bribe and the one who accepts it, and for the one who mediates between them.
Exceptional Cases for bribery
No exception is made except in cases where the bribe is paid to remove injustice or to attain rights which can only be attained through bribery.
In that case, it is permissible for the one who gives it but it is haram for the one who takes it.
So long as the job is based on a test for applicants, bribery is haram in this case, because you were no better than anyone else and you have no particular right which you had to pay a bribe to attain.
Prophetic warning concerning bribery
There is a warning concerning bribery which should scare any wise person away from engaging in it. Abu Hurairah (may Allah be pleased with him) said: The Messenger of Allah (peace be upon him) cursed the one who offers a bribe and the one who takes it. (Abu Dawood, at-Tirmidhi and Ibn Majah)
Is your salary halal?
If you have repented to Allah and you give some money in charity, as you say, then there is nothing wrong with you remaining in this post, so long as you are qualified for it, because appointing someone who is not qualified is a betrayal of trust, the harmful effects of which are obvious to all.
Almighty Allah knows best.