Which type of attack is being utilized when the attacker asks you to hold a security door open for them after you have successfully authenticated using your proximity badge or access badge?

When the attacker asks you to hold a security door open for them after you have successfully authenticated using your proximity badge or access badge backdoor attack is being utilized. The backdoor malware gives you to have normal authentication procedure and the remote access is granted.
This attack exploits vulnerabilities within applications.
Backdoors are used for a number of malicious activities: data theft, server hijacking, Website defacing and many more.