July 20 (UPI) -- Officials said personal information belonging to 1.5 million patients in Singapore, including Prime Minister Lee Hsien Loong, were accessed last month by hackers in the "most serious breach of personal data" in the nation's history.
The cyber attackers also copied outpatient medicine records of 160,000 people, the Ministry of Health and Ministry of Communications and Information said in a joint statement.
The attackers "specifically and repeatedly" targeted the prime minister's personal information about his prescription medicines, something he said was likely a disappointment for the hackers.
"I am personally affected, and not just incidentally. The attackers targeted my own medication data, specifically and repeatedly," Lee said in a Facebook post. "I don't know what the attackers were hoping to find. Perhaps they were hunting for some dark state secret, or at least something to embarrass me. If so, they would have been disappointed."
The breach affects patients who visited SingHealth's specialist outpatient clinics and polyclinics from May 1, 2015 through July 4 of this year. Officials said the data was exfiltrated from June 27 through July 4.
Data accessed and copied included non-medical personal information like the patient's name, identity number, address, gender, race and date of birth. The hackers did not alter or delete the records, officials said.
Medical records including doctors' notes and health scans were not affected.
Lee said he's ordered top cyber officials to work with the Ministry of Health to look into the breach and tighten up defenses, a process he said will "doubtless have valuable conclusions and recommendations, which will help us do better."
"This will be a ceaseless effort. Those trying to break into our data systems are extremely skilled and determined. They have huge resources, and never give up trying," Lee said. "If we discover a breach, we must promptly put it right, improve our systems, and inform the people affected. ... We cannot go back to paper records and files. We have to go forward, to build a secure and smart nation."