Backscatter is the reflection of waves, particles or signals. The term may also refer to: Backscatter X-ray, a new type of imaging technology Backscatter (DDOS), a side effect of denial-of-service attacks on computer resources Backscatter (email), a side effect of e-mail spam, viruses or worms Backscatter (photography), the orb-like image of an out-of-focus particle in a camera's flash