It is possible to hack a VPN, but it would be incredibly difficult, time-consuming, and complex to pull it off. Powerful software and years of work are needed for hacking data that is encrypted by VPN providers. Strict VPN protocols and encryption technology have greatly improved over the years to ensure that you have maximum privacy while you browse the web.
Also, most users download VPN services for similar purposes; entertainment, browsing, and accessing communication apps blocked by the country. Hackers are not motivated to target such users.
However, in case you download malware or viruses often found in spam e-mails on your mobile or computer device, a VPN will not be able to stop these viruses from reacting to your computer or mobile devices.