3Essentials has been seeing an increase in the number of DNN sites actively exploited by a DNN vulnerability in DNN 4.9.2 on customer's DNN installations who have not updated them past the DNN version patched.  Details on the exploit are here:

  http://blog.aggregatedintelligence.com/2010/02/dotnetnuke-version-zero-day.html

3Essentials recommends you upgrade your DNN version to 4.9.4 or better.  BE SURE to request 3Essentials make a BACKUP of your DNN installation BEFORE you do this update, in the event the update encounters problems.  See this article:

http://knowledge.3essentials.com/web-hosting/article/441/Backing-up-your-DNN-site.html

We can also upgrade your DNN verson for you! you may request this service from our Support Staff, please review this article for more information:

http://knowledge.3essentials.com/web-hosting/article/1272/DNN-Upgrade-Services.html