Drever.A is a malicious SIS file trojan that disables the automatic startup of Simworks and Kaspersky Symbian Anti-Virus software. Currently, it is still unverified whether either of these software have protection against such attacks. Drever.A does not affect F-Secure Mobile Anti-Virus.
Drever.A can be disinfected easily by using F-Secure Mobile Anti-Virus available from http://www.f-secure.com/estore/avmobile.shtml. Alternatively, you can uninstall it by uninstalling the Drever SIS file with application manager.