Malware:A generic name for all types of malicious programs: adware, backdoors, rogues, trojans, viruses and worms.
Rootkit.TDSS is a dangerous rootkit infection. Rootkit.TDSS may leave your computer open to outside attacks where it could be controlled by a remote user. Rootkit.TDSS could ultimately result in illegal actions that you may be responsible for. It is very important to realize that Rootkit.TDSS could result in identity theft. Rootkit.TDSS may also hide itself and also block access to various security related sites.
Technical details (How to remove Rootkit.TDSS(pop up))