Late last week, Yahoo announced it had discovered a massive hack dating back to August 2013. This hack predates the hack announced in September, and makes Yahoo the victim of the largest known security breach of one company.

It’s still unclear how many users were impacted, but the company is making affected users change their passwords. Hackers obtained not just passwords, but the answers to security questions, names, dates of birth, and telephone numbers.

If you work with sensitive material, now may be a good time to talk to your IT professional about ensuring your protections are up to date.

By Prasana William