The online security company Kaspersky has reported the presence of dangerous programs in the digital versions of educational content for university students. These essays and texts were found to contain malware of varying severity and virulence. Some were described as capable of infecting whole networks from a single student's PC.
https://www.notebookcheck.net/Kaspersky-claims-to-have-found-malware-in-digital-college-textbooks.434487.0.html