Signed malware coming to a phone near you?

Conventional wisdom has it that mobile platforms like cellphones and PDAs are safer from malware (malicious software) attacks; one reason being the relatively closed nature of such platforms.

In some platforms, such as newer versions of the Symbian operating system, this is enforced in part by mandatory code signing which requires that applications need to be signed by a third party, ensuring (in theory) that they are not malicious.

Assuming that the third party is trustworthy, this system should be foolproof, shouldn’t it? Not always, cautions Trend Micro Inc, a global leader in Internet content security. It says that it has been detecting a new threat to Symbian devices — a malware named SYMBOS_YXES.B.