Your 9 yo installed fake antivirus + search engine hijacker. First of all, what the hell are you doing letting a 9 yo browse on a machine with root privileges? Secondly, that has nothing to do with this story. As the article is wrongly accuses DevShare of being drive-by and malware. It is neither.
I wasn't much older than 9 when I first used a computer, and certainly had root access (I guess that's what you'd call it, because the machine had no notion of multiple users).
An article written by someone with more than 2 brain cells can be found here: http://lwn.net/SubscriberLink/564250/0a106d6379c0d741/