Given the immune environment of bats, it's thought that most hemorrhagic fevers are evolved from them.

https://www.nature.com/articles/s41586-020-03128-0

There has certainly been a lot of press around Kitum cave but there are earlier recorded outbreaks and the pinpoint origin really can't be said definitively since viral studies were pretty cutting edge 50 years ago.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4166725/

https://academic.oup.com/trstmh/article/109/6/366/2461644

Of course, just saying it likely originated from bats doesn't really give the whole current story, there are many mammals that are thought to act as reservoir species so the cat is out of the bag...

https://www.science.org/doi/10.1126/science.1172705?url_ver=Z39.88-2003

https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0004815

Took a little digging but Dorothy Tovar provided some great bat facts in this COVID AMA:

https://www.reddit.com/r/science/comments/ezstsw/science_discussion_series_the_novel_coronavirus/