Security experts have uncovered an ongoing cyber espionage campaign targeting Iran and other Middle Eastern countries that they say stands out because it is the first such operation using communications tools written in Farsi.
Israeli security company Seculert and Russia's Kaspersky Lab said on Tuesday that they identified more than 800 victims of the operation.
The targets include critical infrastructure companies, engineering students, financial services firms and government embassies located in five Middle Eastern countries, with the majority of the infections in Iran.
Seculert and Kaspersky declined to identify specific targets of the campaign, which they believe began at least eight months ago. They said they did not know who was behind the attacks or if it was a nation state.
"It's for sure somebody who is fluent in Persian, but we don't know the origin of those guys," said Aviv Raff, Seculert's chief technology officer.
The Mahdi Trojan lets remote attackers steal files from infected PCs and monitor emails and instant messages, Seculert and Kaspersky said.
It can also record audio, log keystrokes and take screen shots of activity on those computers. The firms said they believe multiple gigabytes of data have been uploaded from targeted machines.
"Somebody is trying to build a dossier of a larger scale on something," Raff said. "We don't know what they are going to do at the end."
Researchers have previously said that nation states were almost certainly behind the Flame virus, which was discovered earlier this year, and Duqu, which was uncovered in 2011.They also included a text file named mahdi.txt in the malicious software that infected targeted computers.