Recently we have faced a Skye virus attack on a LAN. One of the users received a message

Do you think this is the definition of SEXY? I do.
http://www.xxxxxxxxxx.com/uploads/94603/NewPicture004.JPG.zip

Now the same message was started to send from this machine to all his skype contacts. Also sent email through email client.  In a couple of minutes all systems were infected.  We have done the following steps to fix it

1. Cleaned the hosts file
We have noticed that the hosts file  located in c:\windows\sysetm32\drivers\etc\ was edited by the virus and it added many lines to the file at the very bottom.  We  scrolled down to the end and removed all unwanted entries.  Remember  this file is read only and you need to change the file attribute to save it.

2. Cleaned the System using ComboFix

Download this and run the file.  Follow the instructions and complete the steps. In some cases you need to do with something on the Network Card. Go to Device manager and you will find two copies of the same network card. One with an Yellow color and other is normal. Now remove the Normal card and click on Scan for hardware changes and your card will be automatically installed. Note that you may also to set the IP address if you are using static IP address

3.  complete System scan using a good Anti Virus

Use any good anti virus program to do a full system scan. I recommend Avast Antivirus and do a boot time scan with that