Reuploading the files won't remove the message even if that removes the malicious code. You have to go through a process to ask Google to re-evaluate the website, and once they verify the malicious code has been removed, they remove your site from the blacklist your browser is checking. All the information you need is there if you click the button for info on why it was blocked.
Since it's unlikely your own computer at fault with you running Ubuntu, then the problem is at the other end -- you're running code on that website with vulnerabilities allowing someone to put their code in your site, or some software on the server is out of date, etc.
In the meantime, why don't you take the hacked sites out of your signature so you don't end up infecting SitePoint forum visitors? It still has the malicious code on it.