Bitcoin Shadow attack can result in chain reorg which could lead to double spending. Get blockchain certified: https://academy.ivanontech.com join 20,000 students. Bitcoin has a golden rule which says that the chain with the most PoW is the one that all miners need to accept, which could result in shadow mining attacks in which malicious miners try produce a longer chain without triggering the difficulty adjustment algorithm.
BITCOIN MINING ATTACK! Shadow Mining, Chain Reorg, Difficulty and 51% Attack – Programmer explains