There is any way to know in HPSM (triggers) if was added a attachment in a record ?
For example in probsummary?
As already advised to use a trigger for the table.
But when and how do you want to kniw it ?
For example - store in probsummary for each incident flag true if addaed attachments (dont forget to clear it if attachments deleted)
Or you can store in probsummary fro each incident digit - attachments quantity.