Malicious software that blocks access to computers spread swiftly across the world Friday, snarling critical systems in hospitals, telecommunications and corporate offices with the help of a software vulnerability originally discovered by the National Security Agency. Reports of the malware spread began in Britain, where the National Health Service described serious problems. But government officials and cybersecurity experts later described a far more extensive problem growing across the Internet, with tens of thousands of computers in dozens of nations affected. Europe, Asia and Latin America were especially hard hit. Apple became the first U.S. company to top $800 billion in market capitalization, a little more than two years after it crossed the $700 billion threshold. The iPhone maker’s shares have gained 33 percent this year and almost 50 percent since the November elections. Apple represents about 4 percent of the $21.7 trillion that makes up the Standard & Poor’s 500-stock index. A federal appeals court upheld the government’s bailout of American International Group in the heat of the Great Recession. The ruling said a company controlled by ex-AIG chief executive Maurice Greenberg did not have a legal right to pursue its claim against the federal government. Greenberg had alleged that the $85 billion bailout of the teetering AIG in September 2008 violated the Constitution’s Fifth Amendment by taking control of the company without “just compensation.” Barclays will pay $97 million to settle civil charges that it overbilled its asset management business clients for tens of millions of dollars, U.S. regulators said. Barclays declined to comment. Warren Buffett said United Airlines bungled the case of the passenger dragged off a plane last month, and he criticized the chief executive’s handling of the incident. Buffett, whose Berkshire Hathaway is a major shareholder of United and other U.S. airlines, said the spotlight on poor customer service in the airline industry doesn’t change his investment strategy. Berkshire Hathaway is also the top shareholder at Delta Air Lines, No. 2 at Southwest Airlines and No. 3 at American Airlines. Facebook must delete hate speech postings worldwide, an Austrian court said, ruling that Austrian law can be applied to lawsuits against the social media website. Green Party politician Eva Glawischnig sued after comments about her were posted in a fake profile. Bumble Bee Foods has agreed to plead guilty to one count of fixing the prices of canned tuna sold in the United States and to pay a criminal fine of $25 million, the Justice Department said.