There hasn't been a security breach here at KH. What you probably received was some spam send by a spammer who spoofed (faked) a knittinghelp.com email address and used it as the from field in the message. This is a common spam tactic as it masks the true identity of the spammer and causes all the bounces to be returned to the person who was spoofed. The tactic is commonly referred to as Joe Jobbing
. Unfortunately, there's not much protection against a spammer spoofing any old email they want.
We have been noticing a lot of bounce messages coming in from various random knittinghelp.com email addresses indicating that a spammer is indeed spoofing knittinghelp.com addresses for their own purposes. But rest assured, the emails are not coming from this web site or through any hacking of the forum.
I hope this helps.