It was the spring of 2011 when the European Commission discovered it had been hacked. The intrusion into the EU's legislative body was sophisticated and widespread and used a zero-day exploit to get in. Once the attackers established a stronghold on the network, they were in for the long haul. They scouted the network architecture for additional victims and covered their tracks well. Eventually, they infected numerous systems belonging to the European Commission and the European Council before being discovered.

Two years later another big target was hacked. This time it was Belgacom, the partly state-owned Belgian telecom. In this case, too, the attack was sophisticated and complex. According to published news reports and documents leaked by Edward Snowden, the attackers targeted system administrators working for Belgacom and used their credentials to gain access to routers controlling the telecom's cellular network. Belgacom publicly acknowledged the hack, but has never provided details about the breach.

Then five months after that announcement, news of another high-profile breach emerged—this one another sophisticated hack targeting prominent Belgian cryptographer Jean-Jacques Quisquater.