I submit then that the rules need to be changed. A thread with valuable information in it, one that has the capacity to help the members here, shouldn't be removed even if the attachment is removed (unless the hack author requests it be removed too, of course.)
Worst case scenario: lock the thread.
Deleting it only denies the
users the valuable information in the thread. No, new members won't get confused; the thread is locked and soon forgotten.