Troj/Mads-A is a proxy Trojan.
Troj/Mads-A copies itself to the Windows system folder as MDS.EXE and sets the following registry entries in order to be run on system startup:
HKLM\Software\Microsoft\Windows\CurrentVersion\Run\
mds.exe
<system>\mds.exe
HKCU\Software\Microsoft\Windows\CurrentVersion\Run\
mds.exe
<system>\mds.exe
Troj/Mads-A registers itself on a remote website and then functions as a proxy server, allowing remote users to route HTTP traffic through the infected computer.