I don't think these inbreeds morons know how to use cryptocurrencies myself. They'll probably use some archaic form of money just like their worldview.
There are quite a few IT specialists among the ISIS Jihadis in Syria and Iraq. Check the videos and twitter feeds uploaded by these scum, and you'll notice their skills yourself. However, there are some practical difficulties in using the Bitcoin. For example, if they want to exchange their coins to fiat, there are very few people in their territory who accept these coins.