All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
If this account is mainly set up to publish what is forbidden, then it is forbidden for you to promote it, because this will be helping in sin. Allah Says (what means): {…but do not cooperate in sin and aggression.} [Quran 5:2]
If the account rarely publishes what is forbidden, and it is not primarily set up for this purpose and what is forbidden is not predominant in it, then, in order to be on the safe side it is best not promote it in order to avoid indulging in a suspicious situation of helping in what is forbidden. However, we do not authoritatively assert the prohibition of promoting the account in this case, contrarily to the first case.
Allah knows best.