A majority of Allianz Life's 1.4 million US customers had their personal data stolen in cyber-attack. Here's what you need to know.

The U.S. insurance giant tells state regulators that Social Security numbers were among the personal information stolen in its mid-July cyberattack.

Official filings did not state how many people were affected, or what data was compromised, although in a statement to The Register, Allianz said the majority of its 1.4 million customers were impacted.