Nulled theme pros and cons

Nulled themes or open source themes have same risk, though in nulled themes risk are higher as in many cases hackers bind the code with the exploit and leave it on internet and your site get hacked with your confidential data.

Either used free Open source theme from official sources or better buy with a one time investment if you are running a legitimate business, for a dummy or shell business you can just keep it on go just like that with a nulled theme just try some paid plugins for security addons