I believe they were extended in the 8-k filed July 29, 2013.
Item 8.01 - Other Events
On July 16, 2013 pursuant to a resolution of the Board of Directors, the expiration date of all 6,422,124 of the Company’s issued and outstanding warrants was extended for one year from December 31, 2013 to December 31, 2014.
All other terms and conditions of the Warrants remained the same.