Not sure, but the leaves are alternate, so not a lilac. A clear pic of a single shoot with leaves would help; even better, of flowers or fruit if any are present.
Also, what do the leaves feel like, and what do they smell like. My first impression was something like Lindera benzoin, but the leaves don't look as if they have the right texture. The bark is not inconsistent with Lindera spp, though. Still could be something in Lauraceae, especially if there is a spicy scent to the leaves.
Here are some better pictures of the bush. Unfortunately, it has no flowers or fruits. The leaves have no scent when crushed and are not noticeably hairy. Thanks for your help.
