Workaround for the issue where the Behance Publish Service plug-in is missing from Illustrator CC...
You can export artboards from Illustrator and upload them directly to your profile on the Behance website, either as a Work In Progress asset or a Project.
- From Illustrator, export the artboard(s) you’d like to share to your local hard drive.
- Log in to https://www.behance.net/ with your Adobe ID.
- Click My Portfolio to see active Projects and Work In Progress assets.
- Click Add Work to upload the new artboards you exported in Step 1.