Some versions of  have used the hard-coded string this is the encrypt key for Blowfish encryption when communicating with a C2. Later versions have hard-coded keys uniquely for each C2 address.
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: Some versions of  have used the hard-coded string this is the encrypt key for Blowfish encryption when communicating with a C2. Later versions have hard-coded keys uniquely for each C2 address. ### Response: T1573.001.