Netsky.Q was first discovered on March 28 and security experts are unclear whether the virus code has been passed along to other hackers to modify, or if Netsky variants continue to be the work of the original author.
Netsky was first spotted earlier this month as a worm that uses deceptive subject lines to lure users into opening an attachment, which then spreads the virus through the user's hard drive and file-sharing programs.
The rating system is part of Symantec's virus tracking system, which has so far registered just under 400 reports on the progress of Netsky.Q. Previous versions of Netsky were also elevated to a level 3 warning.
According to Symantec, NetSky.Q is designed to trigger infected computers to launch a denial-of-service attack at 5:11 am on April 8 and April 11 against several specific websites, including eDonkey2000 and Kazaa.