For lack of a better term, this is the concept of a spirit or a condition that "sticks" or follows a person.

It can be a series of accidents, but may also be the feeling of a presence that follows. Eyewitnesses portrays that they are followed by a kind of creature.
Spiritual circles interpret this as one has become a kind of "host" for a creature that lacks precisely what one does or represents. Maybe you have a nice family life, or an exciting life event.

These energies can be an annoyance to those, who are experiencing it.

Spiritual circles recommends to loudly denounce - yes - even scare the creature away. Or that one changes the lifestyle. For example, changes to a less stressful life.
An "attached spirit", is seen as an occupational hazard among "Ghost Hunters". The idea, or the fear is, this entity follows one home. Compare it to a visitor takes a flu home from a sick person.

Scientifically it is - like everything paranormal - unexplained at this time.
One theory leans heavily on the concept of "quantum entanglement". This is a relatively new theory that describes that energy and mass can be coupled to each other, with a kind of invisible "thread".  In physics, it is unknown how a such entaglement is made. Therefore it is even more puzzeling how to break entaglement.

"Bad luck" - the feeling of a continued stream of bad luck, is very subjective. It is often debunked by looking at the bad luck at a broader view. For instance, the car has a flat tire, this results of course in the person beeing late for a dinner, the dinner-partner becomes angry . One often discovers, the one event leads to the other - in a socalled "causal chain". In addition, the brain has a fantastic ability to remember only the negative or bad events.