The document http://www.mig-marketing.com/proves/nando/ru/ contains Russian text in an image only, but it links to http://www.mig-marketing.com/proves/nando/ru/firma.html which contains (in addition to text in an image) Russian text in ISO-8859-5 (= ISO Latin/Cyrillic) encoding. This encoding is declared in a meta
tag, but the problem is that the declaration has no effect, since HTTP headers take preference over them, and they say
Content-Type: text/html; charset=ISO-8859-1
(You can conveniently check the HTTP response headers using Firefox with Web Developer Extension and selecting Information → View Response Headers.)
To fix this, contact the web server admin or try and fix it yourself, if the Apache settings allow the use of per-directory .htaccess
files, in which case just create a file with that name (including the leading dot) in the directory containing the Russian files and enter the text
AddType text/html;charset=ISO-8859-5 html
This would then make the server send all .html files in that directory with HTTP headers that specify them as ISO-8859-5 encoded.