(Bloomberg) -- At least six U.S. state governments were hacked by a Chinese state-sponsored espionage campaign that partly took advantage of the widespread Log4j software vulnerability, researchers reported Tuesday. The cybersecurity firm Mandiant Inc. said its investigation began last May, when it examined an unspecified state’s government computer network. Of the six state governments that were hacked, at least two of them were “re-compromised” as recently as last month, the firm said. The company didn’t identify the victims by name. Jen Easterly, director of the U.S. Cybersecurity and Infrastructure Security Agency, said last year that the vulnerability in Log4j, a...