Piggybacking is a form of cyber attack where a hacker(s) gain access to an unauthorized network, computing resource, or even a physical building. They do this by leveraging an insecure (open) network (Wi-Fi), an “unlocked” user device, or through the kindness of a helpful but ill-informed employee who opens a door for an attack approaching the building laden with an absurdly heavy or awkward looking object.
Hacker can gain logical access through an authorized user who is already logged into a session on a device who then walks away from the system; leaving it open for the “attacker” to slip in and steal information. A real world example of this is the process of a person approaching a building with card-restricted access with their arms full, but an access ID card at their side. This attacker will wait to follow a employee of the building and will show their badge access card (a fake) to the employee and implore them to hold the door.
In relation to networks, unsecured (open) wireless networks can be piggybacked, where an unauthorized party (hacker) uses the connection to access the Internet. The usual purpose of piggybacking is simply to gain free network access or to gain illegal physical access to a specific location.
Related Terms: Guest Wi-Fi Network