Inanimate objects are not possessed in the same sense as a person, a human being is possessed. Because of some grievous sin, an object, place or area, a building, or other structure demonic activity affects people who come to this place or have direct contact with a cursed object. The phenomena is local to this infested object and all who come there long enough are affected. If one gets away and distants themselves from this infested object demonic activity ceases.
When people are possessed the devil has some legal right to occupy some part or the whole body of a person. The devil then control the body at times. Why is not understood except in terms of hatred for God and for Mankind who are created in the Image of God.
It has been my experience that people who are addicted to porn like to try to get other people in the same boat as them. Sometimes enough sin leads to possession. Sometimes people will even make a pact with the devil in the high hopes of fulfilling some type of illicit, sinful desire. Then they become possessed willingly and they will try to bring you down with them. If you resist as you should they will make fun of you or harass you in some peer pressure way.
We have to make a stand for God. We also have to work to make a living or should. So right off before diving into this situation at work, say prayers of intersession. This the OP has done. In addition to the Prayer to St. Michael the Archangel, maybe composing a heart felt prayer where one pours out their heart to Jesus Christ. A prayer where one asks God to deliver oneself from evil just as the Israelites were delivered and preserved in the time of Moses.
God parted the sea for the Israelites and He will do the same to preserve us. And we have to remember that they hated Christ first. If they persecute the Master surely they will persecute those who live to serve the Master.
