Belnet said 200 of their customers were affected, including universities, public administrations, and research institutes.
Bringing dormant planes out of storage and making them airworthy requires a significant amount of work. Pilots need to keep up their air miles in order to be able to fly, too.
Environmentalists were protesting at the banking sector's perceived complicity in contributing towards climate change.
The investigation was carried out by UK, Belgian and Maltese forces and found personal details had been stolen along with millions in cryptocurrencies.
Brussels residents profited from a beautiful sunrise across a snow covered city on Tuesday after wintry weather brought freezing temperatures and snowfall over large swathes or northern Europe.
With many EU countries struggling to get people vaccinated against COVID-19 as fast as citizens might like, Belgium is re-evaluating its strategy.