Generic Rootkit.w Trojan is the detection for a driver file dropped by malicious applications to conceal their network activity.

Generic Rootkit.w drops a file on the system, which will then serve as a loader file for additional malware downloaded from the internet. Common applications such as "iexplore.exe," "opera.exe," "firefox.exe" and "svchost.exe" are used in the front end to connect to the internet, since they are common applications which usually bypass firewall or other network related policies.

Files that are downloaded are loaded using the dropped loader component into svchost.exe.

More information can be found at this McAfee page.