Just use a razor bladed scraper remove off the timber and let it be.
Attic wood leaking sap.
To prevent sap from leaking out of deck boards it needs to be finished with paint stain or deck waterproofing.
Similarly when a tree is damaged the sap can bleed out.
When it dries it hardens and becomes difficult to remove creating unsightly spots or bumps in the wood surface.
The sap when in live trees carries nutrients throughout the tree that helps to keep it alive.
You can try removing sap with several different cleaning techniques but there is a chance it will come back.
Much of the wood produced for framing lumber has pitch pockets or areas of crystalized resin.
Amber is fossilized resin.
For a start you need to clean all the sap which is gradually crystallizing on the top of the affected wood.
Amber or rosin is great if you save it and use it for stuff like stickum on tools etc.
The reason it is leaking out of the wood there is because it looks like there was a particularliy resinous knot in the pine.
Attic ambering refers to wooden beams in the attic having sap leak out.
Sap is just sugar and water.
Usually if the wood is properly kiln dried it bakes away.
Treat the knot areas with extra coats of the finishing material.
When it is wet it is sticky and can rub off on clothing or attract dust and dirt.
Turpentine works perfect for this purpose and it will not damage the quality of the wood.
Like kevin said the attic heat restores this to a liquid form and it flows out.
It probably got hot enough in the attic and it melted out this happens over time through many heating and cooling cycles.
While there are complex chemical components found in tree sap it s easy to compare sap to blood.
These materials slow the leakage by clogging the wood grain pores but will not stop it completely.