“BOO/Sinowal.A” problem

hello there!

im having a problem with regards to the BOO/Sinowal.A detection found by Avira AntiVir 9.0.0.386 at the master boot sector HD1 of my computer. the problem is, i cannot remove it. i tried removing it using my antivirus but it fails or having an error. i already tried scanning my pc using another antivirus which is avast! professional 4.8 but nothing was detected.

can somebody help me pls?
tnx a lot!