The U.S. Department of Justice has unveiled the details of a sweeping criminal operation in which North Korean IT operatives, aided by American accomplices, fraudulently infiltrated more than 300 companies—including members of the Fortune 500—generating millions of dollars in illicit income and compromising national security-sensitive data. Federal prosecutors allege that the scheme, which spanned several years, involved North Korean nationals posing as remote IT contractors, using stolen identities of American citizens to gain employment within U.S.-based companies. These impostors reportedly secured jobs at a range of major firms in finance, healthcare, aerospace, and technology—positions that gave them not only a source of income, but access to internal systems and, in some cases, classified intellectual property. The operation was allegedly facilitated...