How do I remove Selfmite worm?
Wipe your phone, and reinstall the OS following the official instructions. Make sure to download the ROM images on a computer that isn't backdoored, and verify the checksums before you install.

That's the only way you'll be able to trust this device with private data again. Since you don't know how this malware was installed, you also don't know what other malware might already be on your phone.