Holcim Romania has said on its website that its account with the Romanian national registry for greenhouse gases was illegally accessed on November 16 and 1.6 million carbon permits went missing.
Subsequently, 600,000 permits have been traced but one million permits, valued by the company at around EUR15m (US$19.6m), are still unaccounted for, Reuters said.
"In the recent event, the use of a computer virus (called Nimkey) was reported," Reuters quoted an EU Commission spokeswoman as saying.
