Troj/Daonol-C is a family of Trojans for the Windows platform.
Members of Troj/Daonol-C typically copy themselves to the Root folder and create some of the following files
<Root>\<random filename>.bat (clean batch file)
<System>\sysaudio.sys
The file sysaudio.sys is a member of Troj/Daonol-Fam.
A registry entry is usually set similar to the following:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32
aux
sysaudio.sys
Troj/Daonol-C attempts to redirect internet traffic from a number of websites.