The US government says businesses must do more to defend themselves against cyberattacks. It is urging them to take "critical steps" to keep operations running.
White House Press Secretary Jen Psaki said business leaders have a responsibility to strengthen their cyber defenses to protect the American public and the country's economy.
The US Department of Justice said it will start to treat certain cybercrimes in the way it does terrorist attacks. US officials suspect some of the people behind the attacks are operating out of Russia. President Joe Biden said he was "looking closely" at the issue.
In the latest attack, hackers broke into the systems of the Massachusetts Steamship Authority, which provides travel to Martha's Vineyard and Nantucket islands. Customers were unable to book tickets online.
The company said the breach didn't affect the safety of its ships, and that radar and GPS systems were operating normally.
Last weekend, hackers broke into the servers of the world's largest meatpacking company, JBS. They forced the closure of processing plants in North America and Australia.
Last month, another group targeted the largest fuel pipeline in the US. It disrupted operations and caused long lines at gas stations along the East Coast.