Gatekeeper also treats applications running for the first time differently than reopened applications.(Citation: TheEclecticLightCompany Quarantine and the flag)(Citation: TheEclecticLightCompany apple notarization )

Based on an opt-in system, when files are downloaded an extended attribute (xattr) called `com.apple.quarantine` (also known as a quarantine flag) can be set on the file by the application performing the download.
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: Gatekeeper also treats applications running for the first time differently than reopened applications.(Citation: TheEclecticLightCompany Quarantine and the flag)(Citation: TheEclecticLightCompany apple notarization )

Based on an opt-in system, when files are downloaded an extended attribute (xattr) called `com.apple.quarantine` (also known as a quarantine flag) can be set on the file by the application performing the download. ### Response: T1553.001.