You will need to deploy an anti-virus product to each machine which is infected with the virus (if you don’t have an anti-virus product on any machines currently this may be all machines on your network) and scan all the machines.
AVG Antivirus is cheap for businesses and free for home users. Symantec, Mcafee, and Trend make good tools as well.
The best thing to do when your computer or network has been infected with a malicious virus or malware infection is to install an effective and updated antivirus software. Make sure that the software you use is licensed by purchasing it to the company, don’t be hesitate about its cost because it could save your computer from your network.