The clean-up following last week's Wannacry ransomware cyber attack continues. The virus crippled a wide range of institutions, from hospitals to factories, across the globe. And experts warn further attacks are likely. 

The Spanish National Cyber-Security Institute (INCIBE), based in Leon, northwest Spain, is an institution for enhancing cyber-security across the country. Last week's Wannacry virus is the largest ransomware attack to have hit the world. Spain was among the countries affected.

Marcos Gomez Hidalgo, deputy director of INCIBE, said that the hackers may be testing further attacks, and updating systems is very important.

At a university in Madrid, students taking a masters degree in cyber-security believe that the attack is a wake up call. 

"This is not a novel threat. This is a threat that we already knew. So I guess this is a nice point to say, alright these kinds of things may happen. This time we have been lucky, but perhaps next time we won't be that lucky," said Jose Maria De Fuentes , one of the lecturers.