Netsky causing billions in damages - News - ZDNet:
"Despite requiring the computer user to actively run an attachment, Netsky.C seems to be spreading fast, with anti-virus vendor Central Command claiming it had discovered 1,500 infections of the virus within 40 minutes of its discovery. Like Netsky.B the latest virus uses its own SMTP engine to e-mail itself to addresses found on the computer, and copies itself into any folder it finds whose name includes 'shar'. "

UK security company mi2g estimated the economic damage done by Netsky.B worldwide to be at least US$3.12 billion. This was calculated "on the basis of helpdesk support costs, overtime payments, contingency outsourcing, loss of business, bandwidth clogging, productivity erosion, management time reallocation, cost of recovery, and software upgrades".…

http://zdnet.com.com/2100-1105_2-5165642.html