Glossary
Tarrask
Malware described by Microsoft in April 2022 that hid scheduled tasks by deleting their SD value in the TaskCache registry key.
Tarrask is the name Microsoft gave to a defense evasion tool used by HAFNIUM, now tracked as Silk Typhoon. Microsoft's April 2022 report describes it creating scheduled tasks for persistence and then deleting the SD value from the task's TaskCache\Tree key, which requires SYSTEM privileges. The task disappears from schtasks and the console but keeps its registry data and XML file.
The name is now used loosely for the technique itself. Detection is covered in Tarrask and hidden scheduled tasks.