fortnight C virus

I have latest Avast version and all updates, but I was notified
by an email server that I am infected with fortnight_virus_C(sqaaaa).

My Avast is not detecting this >:( Why not?

After a Google search and reading about this email virus, I looked for the telltale files “s.htm” and “host”. I had both, and checking my
email signature setting, I found that the s.htm was my signature.
I have deleted the files and signature, but I do not know if this is all I need to do.

Thank you

Avast did not detect it, because they have no “Signiture” for it. If you still have the s.htm you can send it to support@asw.cz so they are able to add it. or follow the instruction on this site: http://www.trendmicro.com/vinfo/virusencyclo/default5.asp?Vname=JS_FORTNIGHT.A

BTW: you should visit the windows update page more often.