TOKYO— Toyota Motor Corp. said it would shut down all 14 of its factories in Japan on Tuesday after a supplier had a computer problem.
The supplier, Kojima Industries Corp., said it believed the problem stemmed from a cyberattack or possibly a malicious email with a virus, but it said the exact cause wasn’t known. Kojima, a supplier of plastic parts for car interiors, said it shut down its servers to prevent the problem from spreading, and its website was down.