has sent spearphishing e-mails with attachments to deliver malicious payloads.(Citation: Proofpoint Operation Transparent Tribe March 2016)(Citation: Kaspersky Transparent Tribe August 2020)(Citation: Talos Oblique RAT March 2021)(Citation: Talos Transparent Tribe May 2021) 
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 sent spearphishing e-mails with attachments to deliver malicious payloads.(Citation: Proofpoint Operation Transparent Tribe March 2016)(Citation: Kaspersky Transparent Tribe August 2020)(Citation: Talos Oblique RAT March 2021)(Citation: Talos Transparent Tribe May 2021)  ### Response: T1566.001.