the texture comes with 3ds max, oh yeah, and try this:-
1. select the sphere
2. goto the modify panel
3. select noise
4. tick/check the box that says fractal
5. go down and set the strength to X-20 Y-15 and Z-20
6. change scale to 25
7. There you go, change the seed value to get different boulder shapes, you can change the strengths aswell to your desire.
hope that helped
(picture included to show you where to select each modifier)
ps. set the segment value to about 15, it will be too high poly to have as an object, but it's up to you really
so what's the job?