The hackers used sensitive data acquired from non-IRS sources - including Social Security Numbers, Date of Births and street addresses - to clear the multi-level security system of the IRS which includes verification through personal questions.
In total, the IRS has said there were 200,000 attempts to get data from their servers. The IRS will provide free credit monitoring service to those affected by this breach of data.
The IRS got to know a couple of weeks back that unusual activity was happening on their servers and that is how they discovered the breach of data.
The 'Get Transcript' feature was shut down temporarily by the IRS to gauge the estimate of the damage caused by the breach.
