I saw this 6 or 7 years ago and even then I thought it looked pretty old so I think it was made in the late 80s – early 00s. It was in color and it was in English.
The whole plot takes place in a rural area, with some forests and log houses. It probably takes place in the modern era. Somehow the creature (alien?) starts possessing other people in town and I vaguely remember the main character was a sibling or a family.
I remember one scene towards the end where the creature takes a form of a small black goo/blob and attacks the main female character from the crotch. I think she died.
Phantoms (1998)?
https://www.imdb.com/title/tt0119891/
No, but thanks. It does seem to match a lot of the descriptions I gave, but I think the main characters lived in a log house or a wood house, and the female character was killed there.
The Messengers (2007)?
https://www.imdb.com/title/tt0425430/
It was definitely a creature panic type of movie than a supernatural/ghost type. It was also of a lower quality but I don’t know if it was because of the age or due to low budget.
Slither 2006? that has blob like alien slugs.