Large-scale international cyberattacks have expanded to at least 150 countries, affecting more than 100,000 organizations, Europol said Sunday. The “ransomware” hacks are being carried out using stolen software from the National Security Agency, and were first carried out against hospitals in the United Kingdom. They have since targeted government institutions. The hackers often demand ransom payments in order to restore access to hacked systems. Jan Op Gen Oorth, a spokesman for Europol, warned that the numbers are likely to increase as people return to work on Monday morning and turn on their computers.