A clever phishing scheme launched last week may have stolen more than €3 million worth of carbon emission permits from companies.
At least seven companies with carbon emission permits registered with the German Emissions Trading Authority saw some 250,000 certificates moved out of their accounts, according to a spokesman with Germany's Federal Environment Agency.
The certificates allow companies to emit pollution within certain limits and are meant as incentives for companies to invest in cleaner technologies. As of Thursday, certificates traded for around €2.50 each, putting the losses at around €3.2 million (£2.8 million).
The attack is believed to be the first ever targeting the emissions-trading program, administered in part by the United Nations.
"We have the impression that they acted very professionally as regards to IT procedures, and of course they had to know how emissions trading works," said Julie Steinen, spokeswoman for German Emissions Trading Authority, the country's registry for carbon emissioin certificates.
Last week, companies whose certificates are tracked by German Emissions Trading Authority receiving e-mails saying they needed to register again due to security problems. The email contained a link to a fraudulent website, Steinen said. Other national registries were also targeted.
Once the fraudsters obtained the companies' account details, they quickly moved the certificates to accounts tracked by other national registries and presumably sold them, Steinen said.
Different national registries track the movement of certificates, but the financial transactions are separate from the registry system, she said. Certificates can be sold on the open market.
Once electronic certificates are moved to another registry, it's more difficult to track them, although the certificates do carry a unique code. Germany's Federal Criminal Police Office and prosecutors in Berlin are investigating, Steinen said.
The German Emissions Trading Authority halted certificate trading last Friday to ensure no other companies were victimized, and other national registries also temporarily closed. Germany's registry, which advised its 2,000 companies to change their passwords, is going to resume allowing transactions today, she said.
The agency has also published a screenshot of what the security certificate for its Web site should look like. Web sites can create a security certificate that is then verified by a third party to show the site isn't a fake one. Web browsers should alert users when a certificate is invalid.
Germany's registry has several security measures in place that companies have the option of implementing that would make it more difficult for the phishers.
One of those is a so-called "four-eyes" system, where if one person initiates a certificate transaction, a second person gets a notification of that request and must log in to approve it. Companies can also opt to receive an e-mail every time their account is logged into, a feature that could prompt a fast alert of an unexpected account access.
Those features may have helped prevent greater losses, Steinen said. Many companies called the agency after seeing the fraudulent e-mail, and asked if it was really from the agency. "The emails were not that professional - other users easily smelled the rat," she said.