5/3: SymbOS/Locknut-C Infects Handsets
May 3, 2005

SymbOS/Locknut.C is malware that appears to only affect Series 60v2 platforms (tested Series 60v1 platforms did not exhibit any symptoms). Locknut.C is part of the payload of the Trojan SymbOS/Yo.A

Yo.A, in turn, was discovered in a submission by a Mobile World Forums user. The payload of this malware is to prevent the use of the infected handset by causing an infinite loop of thread crashes. For the end-user, this manifests as a dialogue box reporting "App.closed AppArcServerThread" that endlessly respawns.

This will render the handset inoperative, and will persist through reboots of the device (assuming that the malware has installed correctly--some variants do not, so the handset may recover after a reboot).

More information can be found at McAfee page.