In some cases, adversary groups may form partnerships to share compromised systems with each other.(Citation: CISA Karakurt 2022)

Footholds to compromised systems may take a variety of forms, such as access to planted backdoors (e.g., [Web Shell](https://attack.mitre.org/techniques/T1505/003)) or established access via [External Remote Services](https://attack.mitre.org/techniques/T1133).
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: In some cases, adversary groups may form partnerships to share compromised systems with each other.(Citation: CISA Karakurt 2022)

Footholds to compromised systems may take a variety of forms, such as access to planted backdoors (e.g., [Web Shell](https://attack.mitre.org/techniques/T1505/003)) or established access via [External Remote Services](https://attack.mitre.org/techniques/T1133). ### Response: T1650.