Try to obtain confidential information from man in pub (5)

'try to obtain confidential information' is the definition.
I can't judge whether this defines the answer.

'man in pub' is the wordplay.
'man' becomes 'his' (I've seen this in other clues).
'in' is an insertion indicator.
'pub' becomes 'ph' (public house).
'his' inserted into 'ph' is 'PHISH'.

'from' is the link.

Can you help me to learn more?