How to get rid of a trojan - BAT/FtpBot.SB!MSR

[AKILBY]

Hi, Using Microsoft Security Essentials, every scan says I have a trojan. BAT/FtpBot.SB!MSR. So I use the remove button, and also empty my recycle box. When I immediate run the scan again , it comes up clean. But the next day the same trojan is detected again, ie it wasn't removed? This has gone on for weeks. How do I permanently get rid of this trojan. Microsoft security essentials only seems to be detecting it, its not deleting it.

It says it's in file:C:\Windows\System32\s if this helps. Most items in this file are dated in 2009, but a few are dated December 2019, is this relevant?

Thanks for your help.

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