| 1. Backdoor access refers to cyber criminals utilising backdoor programs to secure remote access to computers or systems by bypassing normal authentication or encryption. Once backdoor access is granted, the compromise activities begin.
Related Term: Configuration Exploitation
2. Backdoors, along with C2 functionalities, are one of the most common footholds into internal networks. Once threat actors have a foot in the backdoor, they begin their post-compromise activities. Through this access vector, threat actors can now drop additional malware to perform a myriad of tasks, including capturing keystrokes, that lead to compromised accounts, escalated privileges, and movement to other areas in the victim’s network, as well as establishing exfiltration points and methods for sensitive data.
Source: (Verizon, 2016)