Washington ? Symantec Corp.’s leading antivirus software, which protects some of the world’s largest corporations and U.S. government agencies, suffers from a flaw that lets hackers seize control of computers to steal sensitive data, delete files or implant malicious programs, researchers said Thursday.

Symantec said it was investigating the issue but could not immediately corroborate the vulnerability. If confirmed, the threat to computer users would be severe because the security software is so widely used, and because no action is required by victims using the latest versions of Symantec Antivirus to suffer a crippling attack over the Internet.

Researchers from eEye Digital Security Inc. of Aliso Viejo, Calif., discovered the vulnerability and provided evidence to Symantec engineers this week, said eEye’s chief hacking officer, Marc Maiffret.

Consumer versions of Symantec’s Norton Antivirus software are not vulnerable to the flaw, according to eEye.