Researcher Duo Security says some Apple Macs are being exposed to security risks because their core software is outdated.
Duo Security found that 4.2 percent of the 74,000 Macs it tested ran insecure versions of software that helps get the machines running. It said the figure was likely to be replicated in the global population of Macs and worse on PCs.
Apple welcomed the research and said it was improving how it updates machines.