/Volumes/EFI - Firmware.scap & MBA41_0077_B12_LOCKED.scap
MBA41_0077_B12_LOCKED.scap is the payload of the EFI 2015-001 Security Update provided by Apple. It's visible in the EFI partition because your Mac can flash scap files (ROM updates) only from an EFI partition (fat32).

Firmware.scap is part of your OS X. The file is needed in the boot process (that is why you can see it in your EFI partition ) and is taken (copied) by OS X, during the boot, from /usr/standalone/i386/

Their presence in the EFI partition is not necessary (as MBA41_0077_B12_LOCKED.scap has already been flashed to the ROM and Firmware.scap if removed would be copied back), they are not malicious files.