Industrial & Commercial Bank of China, the world’s largest bank, paid $1 for its place on Wall Street. It got more than it bargained for.

The Chinese lender acquired a small New York broker-dealer in 2010, a move that extended its presence into the US securities industry. It is now dealing with the fallout from a cyber attack this month that crippled that business and briefly triggered widespread concerns about the fragility of the largest cash market in the world.