There is no such thing as "or after" the auxiliary. The negative of these forms is formed by wrapping the ne+pas/whatever circumfix around the auxiliary and any accompanying pronoun:

Je ne m’en suis pas moqué.

Je ne l’ai pas frappé.

etc.

In most spoken forms of French (and writing that emulates them), the ne is almost universally dropped, which is the only way I can think of that one could describe a negative as being placed "after" the auxiliary.

in passé composé most of the adverbs come in between the auxiliary verb and the past participle.

example:

• Je ne suis jamais allé en France.
• Je n’ ai rien compris.
• Je n’ ai pas encore mangé.

BUT:

• Je n’ ai vu personne.
• Personne n’ est venu.
• Rien n’ a changé.

NOTE: Adverbs of place and time come after the past participle

example:

• Nous avons parlé hier.
• Je ne suis allé nulle part.

SOURCE: apprenons le français- méthode de français (4)

The above picture gives a basic explanation of negative expressions au passe(https://i.stack.imgur.com/IvYXb.jpg)