The problem came to my knowledge a couple of months ago so this advice may be "old hat". Maybe Windoze Updates will now fix it.
The problem relates to an exploit which attacks people through open ports. That affects the netapi32.dll which should be easily fixed.
Download/install/run Windows Worms Door Cleaner .........
http://www.firewallleaktester.com/tools/wwdc.exe
(Close all ports as well).
OJ