Two years ago, a Spanair passenger plane crashed only moments after it took off from the Barajas airport in Madrid, killing 154 of the 172 people on the flight.

Why did the crash happen? Spanish newspaper El Pais says that the company's internal investigation discovered that at the time, the airline's central computer system - the system that should have registered technical problems affecting the plane - was infected with Trojans, and that this may have prevented it from reporting the danger.

It definitely isn't only the fault of the infected system. According to The Register, the plane took of the runway with flaps and slats retracted, a fact that should have been noticed by the pilots or at least by the plane's internal system.

But, since the plane was experiencing problems only the day before, and the pilots already tried to take off and failed before the final, disastrous attempt, the central system should have prohibited further use of the plane.

Which Trojans were to blame for the accident is yet unknown. A final report should be issued in December, after a formal investigation by the authorities that will also look into whether the mechanic who checked the plane before the fatal take-off and the airport maintenance chief are partly to blame for the disaster.