I am looking for some tools to help me with security test on a desktop application, but I haven't figured it out yet. Any help will be highly appreciated.
OWASP is for the web, it is in the name. For desktop applications, the only one I know of is IBM Security AppScan. A scanner is not going to find everything. The best thing is hiring a professional. At a previous job we hired Accunetix and I learned a lot by reproducing the issues they found (so I could make sure they were fixed). Check out this SO question on the same topic.