Studies have uncovered that several individuals used front organizations to purchase drones and equipment in Western Europe for shipment to ISIS. In one instance, two Bangladeshi brothers used their business activities in the UK, Bangladesh, Spain, Australia, the US, and Denmark to supply IT services and drones to ISIS. Elsewhere, Turkish distributors were discovered, and some sanctioned, to have supplied drone components to the terrorist organization. Investigations have measured that the vast majority of weapons and ammunition in ISIS supply chains were of Warsaw Pact country origin (China, Russia, Eastern European), and about 30% from the EU. With the de facto collapse of ISIS control over territory, it is uncertain how their supply chain will adapt and whether they will continue to source materials and equipment from Western Europe.
Source: Is ISIS buying valuable military equipment in Western Europe?