WASHINGTON — The Obama administration is preparing an executive order with new rules to protect US computer systems, after Congress failed earlier this summer to pass a cybersecurity bill. The provisions include voluntary standards for companies, a special council run by the Homeland Security Department, and new regulations covering especially vital systems, according to a draft proposal obtained by the Associated Press.

But just weeks before the election, the White House risks complaints that President Obama is antibusiness from Republicans and the same probusiness groups that killed the plan on Capitol Hill.

National security officials have warned that electric grids, water plants, banks, and other essential industries operated by the private sector are vulnerable to cyberattacks. Yet there are deep divisions over the best approach for keeping hackers and other criminals, foreign governments, or terrorist groups from penetrating these systems.

Critical infrastructure systems provide services that are part of everyday life. But an enemy with the proper know-how could cause catastrophic damage and chaos by giving the systems incorrect commands or infecting them with malicious software. Potential nightmare scenarios include high-speed trains being put on collision courses, blackouts that last days or perhaps even weeks, or chemical plants that inadvertently release deadly gases.

‘‘If those intruders get into those systems and then can determine how they can in fact interfere in the command and control systems of these systems, they can do things,’’ White House counterterrorism adviser John Brennan said last month.