Euonymus are frequently plagued with this insect, so preventative sprays often help. Back to top I have several Euonymous shrubs that are infested with aphids. I have sprayed with a pesticide. I have read where ladybugs are a good way to get rid of them or just spraying with a hose. They are small insects and you should see them move around.
Scale insects are much more common on Euonymus plants than aphids.
If it is definitely aphids, lady bugs work very well. Some local nurseries carry live insects, or you can mail order them. I ve enclosed some for you to see. Can you tell me what to do, because I m afraid it is dying. The golden euonymus is covered with a scale insect.