Is it permissible for an employee entrusted with a financial deposit to place it in his personal investment account and take the profits generated from this deposit while the full amount of the deposit remains intact?

This investment account in a usurious bank is a forbidden transaction, and not only for the trust money, but also for the questioner's own money. Any profits generated from it are forbidden usury (riba), which is unlawful to possess. It must be disposed of by spending it on the welfare of Muslims and charitable causes.