has commonly created Web shells on victims' publicly accessible email and web servers which they used to maintain access to a victim network and download additional malicious files.
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: has commonly created Web shells on victims' publicly accessible email and web servers which they used to maintain access to a victim network and download additional malicious files. ### Response: T1505.003.