Andrew Brookes, Getty Images/Cultura RF

Computer code associated with a Russian hacking effort was found at a Vermont utility but wasn’t used to disrupt its operations, according to a report late Friday.

The penetration of the Vermont utility may have been a test to see whether hackers could get inside the US electrical grid, The Washington Post reported, citing unnamed US officials. The code found at the utility is associated with Grizzly Steppe, the Department of Homeland Security’s name for a Russian hacking operation.

Federal officials shared the Grizzly Steppe code with executives earlier this week and it was identified in the Vermont utility on Friday, according to the report. It’s unclear when the code first entered the Vermont utility.

The Department of Energy didn’t respond to a request for comment on the report. The Department of Homeland Security couldn’t be reached for comment.

The Russian Embassy didn’t respond to a request for comment.

The report comes as tensions between the US and Russia over hacking heat up. On Thursday, the Obama administration sanctioned nine entities and individuals and is expelling 35 Russian diplomats after federal investigators found Russia had tried to interfere with the US presidential election by hacking and releasing emails associated with Democratic nominee Hillary Clinton.

Russia has denied any involvement in hacking directed at the US election.

Utilities and banks have been hacked before. Iranian hackers were indicted earlier this year for allegedly hacking a US bank and a New York dam. Separately, parts of Ukraine’s power grid were taken down in a hack some researchers have attributed to Russian activity.