How we change what others think, feel, believe and do
Attacking during a conversation is using destructive argument designed to either demolish an argument that is being presented, or even as an attack on a person, intended to create fear, demoralize them or otherwise prompt concession.
Attack is often signified in the vehemence of words used and aggressive body language, although it may also be done politely, with cunning insinuation and oblique criticism.
The data you are using is incomplete and no longer relevant.
That's a rather stupid argument.
There you go again. When will you ever learn?
A problem of attack is that it cues the fight-or-flight reaction. 'Flight' can be a retreat into concession, which is what is really sought, though it can become a more complete retreat as the person physically leaves. 'Fight' involves defending or launching counter-attack that can damage the relationship further without resolving the conversational difference.
Attack is more than disagreeing as it seeks to destroy rather than presenting an opposing viewpoint. It presumes the attacker has greater power and assumes they will win any conflict. The shock value of attack may even be enough to cause concession, even if the attacker has limited power.
One way that attack can be deliberately used is to provoke a counter-attack. This may be done in order to take attention away from a conversation which is heading in a direction that may be very uncomfortable for you (in fact so uncomfortable, a destructive argument is preferable).
Although they can be used as deliberate provocation, conversational attacks are often unsophisticated tactics used by people who know no other way.
If attack must be conducted, then it is best done when you have greater power and can hence be assured of winning any direct conflict. Even then, though, the weaker party may resort to vengeful subterfuge that causes subtle future damage.