"I'm very pessimistic on weapons of mass destruction generally although I don't think that nuclear probably is quite as likely as either primarily biological and maybe cyber," Buffett said during Berkshire Hathaway's annual shareholders' meeting on Saturday.
BUFFETT: This is 'the number one problem with mankind' (BRK.A, BRK.B)
Warren Buffett sees cyber attacks as a bigger threat to humanity than nuclear weapons.
"I don't know that much about cyber, but I do think that's the number one problem with mankind."
Last year, Buffett said CNBC — cyber, nuclear, biological and chemical attacks — posed a major threat to the economic well-being of Berkshire shareholders.
In 2015, Berkshire made a bet that could profit from increased cyber breaches. Berkshire Hathaway Specialty Insurance launched two insurance policies that cover cyber liability and the costs incurred to respond to a data breach or threat.
Similarly, AIG launched a product earlier this year that covers expenses arising from online bullying and extortion, according to Fortune.