When MS released their Antispyware beta (aka Giant's Software) we downloaded it to test in our non-production lab. They did not go through the code very thoroughly when 'slapping' the Microsoft logo on it. When it errors out periodically the window header says 'Giant Software', also it appears this way in the event logs.

So if any of you are running this in production and happen to notice a large quanitity of 'Giant Software' in your event logs, don't panic, it's just MS Antispyware beta doing what betas do best.