The lawsuit seeks $3.9 million in damages and civil penalties.
The owner of the now-defunct company, Anita Mahajan, is faced with criminal charges stemming from the alleged fraud.
Mahajan was involved in real-estate transactions that in 2006 netted Patti Blagojevich $113,000 in commissions. Mahajan's husband, Amrish, was a major fundraiser for the impeached ex-governor in the Indian-American community.
In a prepared statement, Madigan said her office will take every action necessary to recover the taxpayer money that this company wrongfully obtained."
The Associated Press contributed to this report.