Maan (Arabic) has a story about a ring of counterfeiters making Israeli 10-shekel coins. They can be identified by the sound they make when clanged together.Since they are not worth much, the main victims have been the poorer Palestinian Arabs in the West Bank, and children, who get paid with these coins and then find out that they are worthless.
Ma'an notes that Hamas had counterfeited other currencies to pay Egyptians for products when Rafah was breached last month, and beyond that some sources say that the Gazans paid the Egyptians literally with Monopoly versions of Israeli currency that the Egyptians were not familiar with.