From TS Daily ( Formally Tom's Hardware News )

Virus writers - no doubt inspired by news of the first PlayStation Portable Trojan - have created the first malware to target the Nintendo DS handheld gaming console.

The simple Trojan, dubbed DSBrick, overwrites critical memory areas, preventing the console from booting up normally and thereby turning it into an expensive paper weight.
http://www.tgdaily.com/2005/10/12/nintendods_trojan/
Virus writers create Nintendo DS Trojan | TG Daily