Exam ECSAv10 topic 1 question 33 discussion

An attacker targeted to attack network switches of an organization to steal confidential information such as network subscriber information, passwords, etc. He started transmitting data through one switch to another by creating and sending two 802.1Q tags, one for the attacking switch and the other for victim switch. By sending these frames. The attacker is fooling the victim switch into thinking that the frame is intended for it. The target switch then forwards the frame to the victim port.
Identify the type of attack being performed by the attacker?