http://www.cs.ucsb.edu/~seclab/projects/voting/index.html
The Report
Our team focused on the security analysis of the Sequoia voting system. Our public report can be found here (a local copy can be found here). We found a number of major flaws that can be exploited to compromise the integrity, confidentiality, and availability of the voting process.
In particular, we developed a virus-like software that can spread across the voting system, modifying the firmware of the voting machines. The modified firmware is able to steal votes even in the presence of a Voter-Verified Paper Audit Trail (VVPAT).