We've previously warned about the Conficker (also known as Downad) virus. It springs from a vulnerability found late last year, for which patch updates were made available in October.
Most of our clients were okay - solid maintenance has kept people safe, but one or two clients were infected unavoidably. It certainly caused havoc all over the place, as one of the fastest spreading viruses ever encountered, it spread across the globe infecting governments and businesses alike. It even attracted a bounty with Microsoft and others offering a reward for identifying the villans who caused this.
Until recently, it has also been known as the 'mystery virus' because no one knew what it as supposed to do. Well, it seems that some of the mystery is being revealed. Rumours are circulating that whatever it does, April 1st will be the day. It seems that the virus writers will try some how to gain control of infecting machines all around the world, and direct them to whatever their nefarious purpose is. I dare say we'll find out next week. Check out the PCMAG summary
here
In the meantime, keep your antivirus up to date. Keep your backups safe. This is probably a storm in a teacup, but some elementary precautions can't go amiss.