'top' shows 'echo "find"' processes using 100% CPU time

I have an Ubuntu 14.04 server, and found that some processes are running with root privileges and takes all my processor time. The processes are called 'echo "find"'. What are these, and how can I stop them?

echo "find" processes


You can check its process ID, with ls -l /proc/1639
and trace its activity with sudo strace -p 1639

According to this thread it's a malware with root permissions.