Disallow task scheduler to start computer

Question

My computer started itself at exactly 9:41pm the last 3 days. And I had the same thing happening at 3:00am in the past. It was always some stupid scheduled task. The fact that a scheduled task can start my computer out of its hibernate state angers me like crazy. Is there any way to prevent this from happening? Pulling the battery out of my notebook every time is not an option. And it needs to be hibernated, not shut down.

I'm on Windows 8.1 Pro with WMC (x64). In the past this happened to me on Windows 7 Ultimate x86.

This is the task that started my computer today, yesterday when I checked it didn't exist:

<?xml version="1.0" encoding="UTF-16"?>
<Task version="1.4" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
  <RegistrationInfo>
    <Source>Microsoft Corporation.</Source>
    <Author>Microsoft Corporation.</Author>
    <Description>Initiates scheduled install of updates on the machine.</Description>
  </RegistrationInfo>
  <Triggers>
    <TimeTrigger>
      <StartBoundary>2015-06-06T20:57:57Z</StartBoundary>
      <Enabled>true</Enabled>
      <RandomDelay>PT1M</RandomDelay>
    </TimeTrigger>
  </Triggers>
  <Principals>
    <Principal id="LocalService">
      <UserId>S-1-5-18</UserId>
      <RunLevel>LeastPrivilege</RunLevel>
    </Principal>
  </Principals>
  <Settings>
    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
    <DisallowStartIfOnBatteries>false</DisallowStartIfOnBatteries>
    <StopIfGoingOnBatteries>false</StopIfGoingOnBatteries>
    <AllowHardTerminate>true</AllowHardTerminate>
    <StartWhenAvailable>true</StartWhenAvailable>
    <RunOnlyIfNetworkAvailable>false</RunOnlyIfNetworkAvailable>
    <IdleSettings>
      <Duration>PT10M</Duration>
      <WaitTimeout>PT1H</WaitTimeout>
      <StopOnIdleEnd>true</StopOnIdleEnd>
      <RestartOnIdle>false</RestartOnIdle>
    </IdleSettings>
    <AllowStartOnDemand>true</AllowStartOnDemand>
    <Enabled>true</Enabled>
    <Hidden>false</Hidden>
    <RunOnlyIfIdle>false</RunOnlyIfIdle>
    <DisallowStartOnRemoteAppSession>false</DisallowStartOnRemoteAppSession>
    <UseUnifiedSchedulingEngine>true</UseUnifiedSchedulingEngine>
    <MaintenanceSettings>
      <Period>P1D</Period>
      <Deadline>P1DT1S</Deadline>
      <Exclusive>false</Exclusive>
    </MaintenanceSettings>
    <WakeToRun>true</WakeToRun>
    <ExecutionTimeLimit>PT72H</ExecutionTimeLimit>
    <Priority>7</Priority>
  </Settings>
  <Actions Context="LocalService">
    <ComHandler>
      <ClassId>{F3B4E234-7A68-4E43-B813-E4BA55A065F6}</ClassId>
    </ComHandler>
  </Actions>
</Task>