This Matthew's powershell script should do the trick:

while ($true)
{
  $pos = [System.Windows.Forms.Cursor]::Position
  $x = $pos.X+1
  $y = $pos.Y+1
  [System.Windows.Forms.Cursor]::Position = New-Object System.Drawing.Point($x, $y)
  Start-Sleep -Seconds 1
}

reference: https://gist.github.com/MatthewSteeples/ce7114b4d3488fc49b6a