KPN discovered the attack last Thursday. It affected the InternedServices unit, which is used by about 280 small business customers.

“We immediately took the servers off the air. As a result, the customers were temporarily unable to use their mail and internet. Two out of three customers are now back on the air,” explains a spokesperson for the provider.

The investigation into the attack is still ongoing. “We have found traces that the perpetrators have actually been inside. That does not mean that they have stolen data or have looked somewhere. But we cannot exclude it yet.”

KPN does not yet know who carried out the attack and what they were looking for. The company also doesn’t know if it was a targeted attack, or if the attackers saw a hole and seized the opportunity. “You have to ask the perpetrators themselves. In any case, we have not yet been approached by parties who say they are behind the attack”.