The sources, who spoke on condition of anonymity to discuss non-public information, said the tools and techniques used in the attacks showed they were part of an ongoing hacking campaign that U.S. officials and cybersecurity researchers have attributed to North Korea.
The campaign has previously focused on defence companies and media organisations but pivoted to COVID-related targets in recent weeks, according to three people who have investigated the attacks.
Cyberattacks against health bodies, vaccine scientists and drugmakers have soared during the COVID-19 pandemic as state-backed and criminal hacking groups scramble to obtain the latest research and information about the outbreak.
Western officials say any stolen information could be sold for profit, used to extort the victims, or give foreign governments a valuable strategic advantage as they fight to contain a disease that has killed 1.4 million people worldwide.
Microsoft said this month it had seen two North Korean hacking groups target vaccine developers in multiple countries, including by “sending messages with fabricated job descriptions.” Microsoft did not name any of the targeted organisations.
South Korean lawmakers said on Friday that the country’s intelligence agency had foiled some of those attempts.
Reuters has previously reported that hackers from Iran, China and Russia have attempted to break into leading drugmakers and even the World Health Organisation this year. Tehran, Beijing and Moscow have all denied the allegations.
Some of the accounts used in the attacks on AstraZeneca were registered to Russian email addresses, one of the sources said, in a possible attempt to mislead investigators.
North Korea has been blamed by U.S. prosecutors for some of the world’s most audacious and damaging cyberattacks, including the hack and leak of emails from Sony Pictures in 2014, the 2016 theft of $81 million from the Central Bank of Bangladesh, and unleashing the Wannacry ransomware virus in 2017.
Pyongyang has described the allegations as part of attempts by Washington to smear its image.