The Format.A and Tahen (variants A and B) Trojans can infect Sony's PSP (PlayStation Portable) and Nintendo DS, respectively, according to security firm Panda.
These three Trojans are described as "extremely dangerous" as their attacks delete critical files, and can even irreversibly render the PSP console unusable.
In order to spread, Format.A is designed to imitate a tool developed to run unsigned code on PSP consoles. The Tahen Trojans, on the other hand, purport to be homebrew applications for Nintendo DS. However, when users install them, they overwrite certain areas of firmware on the Nintendo DS console and the G6, XGFlash, SuperCard and GBAMP devices (which allow cartridges to be recorded with software to run on the console).
Luis Corrons, director of PandaLabs, said: "The videogame consoles are not designed for using third-party software. In order for the malicious codes detected so far to reach one of these consoles, users would have to voluntarily run applications from unauthorized sources."
Corrons does not believe that these console viruses current represent a serious problem to owners of the affected devices but he did not rule out that they could form the first wave of a growing plague of malware affecting video games.
"At present, all we can say with certainty is that malicious code similar to that so far detected will continue to appear, given that the instructions for creating them are readily available on the Internet," Corrons said.
"The chances of malicious code appearing that represent a serious threat to all users of these devices depend largely on the functionalities that developers include in the new versions of these products and the corresponding security measures implemented."