(CNN) -- Could this be the deadliest smartphone app ever?
A German security consultant, who's also a commercial pilot, has demonstrated tools he says could be used to hijack an airplane remotely, using just an Android phone.
Speaking at the Hack in the Box security summit in Amsterdam, the Netherlands, Hugo Teso said Wednesday that he spent three years developing SIMON, a framework of malicious code that could be used to attack and exploit airline security software, and an Android app to run it that he calls PlaneSploit.
Using a flight simulator, Teso showed off the ability to change the speed, altitude and direction of a virtual airplane by sending radio signals to its flight-management system. Current security systems don't have strong enough authentication methods to make sure the commands are coming from a legitimate source, he said.
"You can use this system to modify approximately everything related to the navigation of the plane," Teso told Forbes after his presentation. "That includes a lot of nasty things."
He told the crowd that the tools also could be used to do things like change what's on a pilot's display screen or turn off the lights in the cockpit. With the Android app he created, he said he could remotely control a plane by simply tapping pre-loaded commands like "Please Go Here" and the ominous "Visit Ground."
Teso says he developed SIMON in a way that makes it work only in virtual environments, not on actual aircraft.
"His testing laboratory consists of a series of software and hardware products, but the connection and communication methods, as well as ways of exploitation, are absolutely the same as they would be in an actual real-world scenario," analysts at Help Net Security wrote in a blog post.
Teso told the crowd that he used flight-management hardware that he bought on eBay and publicly available flight-simulator software that contains at least some of the same computer coding as real flight software.
Analyst Graham Cluley of Sophos Security said it's unclear how devastating Teso's find would be if unleashed on an actual airplane.
"No one else has had an opportunity to test this researcher's claims as he has, thankfully, kept secret details of the vulnerabilities he was able to exploit," Cluley said. "We are also told that he has informed the relevant bodies, so steps can be taken to patch any security holes before someone with more malicious intent has an opportunity to exploit them."
Teso said at the summit that he's reached out to the companies that make the systems he exploited and that they were receptive to addressing his concerns. He also said he's contacted aviation safety officials in the United States and Europe.
"From the sound of things, this researcher has got himself a lot of media attention, but still believes in responsible disclosure, rather than potentially putting aircraft and passengers at risk," Cluley said.
Teso isn't the first so-called "white hat" hacker to expose what appear to be holes in air-traffic security.
Last year, at the Black Hat security conference in Las Vegas, computer scientist Andrei Costin discussed weaknesses he said he found in a new U.S. air-traffic security system set to roll out next year. The flaws he found weren't instantly catastrophic, he said, but could be used to track private airplanes, intercept messages and jam communications between planes and air-traffic control.