Adversaries in possession of credentials to [Valid Accounts](https://attack.mitre.org/techniques/T1078) may be unable to complete the login process if they lack access to the 2FA or MFA mechanisms required as an additional credential and security control.
Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request. ### Instruction: List the MITRE techniques contained in the text. ### Input: Adversaries in possession of credentials to [Valid Accounts](https://attack.mitre.org/techniques/T1078) may be unable to complete the login process if they lack access to the 2FA or MFA mechanisms required as an additional credential and security control. ### Response: T1621.