Email users perplexed by the barrage of German-language spam waiting in their inboxes yesterday morning can point the finger of blame at the latest version of the Sober mass mailing worm which began rapidly spreading over the weekend.

Sober.q uses both German and English-language messages to direct recipients to websites with right-wing German nationalistic content, according to an advisory from email security company MX Logic. One of the URLs points to the website of the right-wing German NPD party.

The security firm says that it had seen over 125,000 instances of Sober.q over Saturday night and into Sunday, and labelled it as a high-severity threat.

The variant is downloaded by computers already infected by the Sober.p worm, which circulated earlier this month. The virus writers appear to have remote control over the Sober.p infected machines, giving them a network from which to launch future spam and denial of service attacks.

The latest Sober variant is one of a relatively new type of "propaganda spam," meant to spread political messages rather than sell a product or service, MX Logic says. Circulation of the worm coincides with ceremonies marking the 60th anniversary of the end of World War II in Europe and examples of subject lines it sends include "Dresden 1945" and "Du wirst zum Sklaven gemacht!!!" ("You are made slaves!!!"), according to MX Logic.

"We are certainly seeing more propaganda spam," says Graham Cluley, senior technology consultant with Sophos. Security researchers began detecting religious spam selling a particular view of life last year, Cluley says.

Although Sophos is seeing a lot of German-language spam sent by the new Sober variant, the worm itself doesn't appear to be spreading anymore, Cluley says.

Email users are advised to update their spam filters to guard against the new Sober spam.