To everyone having this issue... bruteforge binary is linked with only one shared library:
You have to locate the library:
# find / -name libgmp.so
1. if you have no output you have to install gmp (gmplib.org), ask your package manager about;
in my system is located in a usual place such as ‘/usr/local/lib’ or ‘/usr/lib’, so bruteforge can load in memory the library and run!
2. If the library is not located in one of these directories it must be added to the load path.
The simplest way to set the load path is through the environment variable LD_LIBRARY_PATH.
Anyway, get a look at here and use your mind.
3. If you have a different version of that library, try to update the symbolic link, letting point libgmp.so.10 to your installed version, for example now I have this:
# ls -ln /usr/lib/libgmp.so*
lrwxrwxrwx 1 0 0 16 Feb 16 15:41 /usr/lib/libgmp.so -> libgmp.so.10.0.4
lrwxrwxrwx 1 0 0 16 Feb 16 15:41 /usr/lib/libgmp.so.10 -> libgmp.so.10.0.4
-rwxr-xr-x 1 0 0 399968 Feb 16 15:41 /usr/lib/libgmp.so.10.0.4
first two rows are symbolic links to the real library libgmp.so.10.0.4, watch also file dimensions...
4. If you can't resolv this issue, grab this static version of bruteforge and you'll get it running!