That's only partially true. It acts like that
only between the 1st and 20th of each month since it is actively probing for other sites to infect. The 21st through the balance of the month it is performing a DoS attack on IP that used to belong to whitehouse.gov and otherwise most servers perform pretty normal during this.
Don't get lured into a false sense of security. If you run Windows check your server and install the patches.