What is the hidden process?

[James Brown <jbrownfirst@gmail.com>]

`unhide` define that there is a hidden process in my system, but don't
indicate it concretely:
> ~$ sudo unhide sys
> Unhide 20100201
> http://www.security-projects.com/?Unhide
> 
> 
> [*]Searching for Hidden processes through kill(..,0) scanning
> 
> [*]Searching for Hidden processes through  comparison of results of system calls
> 
> [*]Searching for Hidden processes through getpriority() scanning
> 
> [*]Searching for Hidden processes through getpgid() scanning
> 
> [*]Searching for Hidden processes through getsid() scanning
> 
> [*]Searching for Hidden processes through sched_getaffinity() scanning
> 
> [*]Searching for Hidden processes through sched_getparam() scanning
> 
> [*]Searching for Hidden processes through sched_getscheduler() scanning
> 
> [*]Searching for Hidden processes through sched_rr_get_interval() scanning
> 
> [*]Searching for Hidden processes through sysinfo() scanning
> 
> HIDDEN Processes Found: 1


How can I find out what is that process?