I noticed that Firefox has decided to block some EXE installers from my site, showing a label Blocked: May contain virus or spyware. I right-click the file, select Unblock, and this message is shown with the Unblock Anyway and Keep me Safe options: The file contains a virus or other malware that will harm your  computer. You can search for an alternate download source or continue anyway.Notice that the dialog does not say may; it says will harm your computer.On what basis is this warning being shown? No one knows for sure which provider Chrome and Firefox are using for their extensive list of false positives. Some say that the site stopbadware.org is responsible, but I'm not so sure.Please advise on how to proceed to restore what's left of my sites and software reputation in an immediately effective way, before it's too late.Thank you.For those asking about the site and software, it's this: http://www.andreszsogon.com/grf-wizard/The software is mine. It's a simple GUI for a command line tool; I developed it with VB6, compressed the app's EXE with UPX compressor, built the installer with Inno Setup, then uploaded it via FTP. I invite you to install it, test it and scan it all you want.
Firefox accusing me of distributing malware on my site
google chrome;firefox;malware
Before getting too caught up in your anger against Firefox and Google Safe Browsing, the first step is to figure out whether Google Safe Browsing is right.  It's not uncommon for sites to distribute executables that contain malware or viruses, without realizing they're doing it.  Often, Google Safe Browsing is right and the site maintainers just weren't aware of the situation -- sometimes their site was hacked, or sometimes someone uploaded some files that are virus-infected without realizing it.So, start by taking a close look at your site to see if any of your downloads are possibly problematic.  You can start by perusing the Webmaster Help from stopbadware.org and Google's Webmasters help for hacked sites.  Then, there are a few general steps you should be taking:Check whether there's any malware on your site. You need to scan your site carefully to check whether any of the file downloads are dangerous or contain viruses/malware.  You can start by using Google Webmaster Tools to check what bad files Google detected.  You should also look at the detailed diagnostic page from Google Safe Browsing and look closely at the specific pages and files listed there.  You can view the diagnostic page here to see which pages specifically triggered the listing.  I also suggest that you upload each of the EXE's you make available on your site to VirusTotal and check them for viruses.Check whether your site has any security holes or has been hacked.  Often, what happens is that hackers find a site that has some security holes, compromise the site, and modify it to insert malware onto the site.  The first the site administrators learn of this is when they get listed on Google Safe Browsing.  So, you should check carefully whether this has happened to you.  Here are a few free services that will scan your website for you:Sucuri site scanSparkTrust site scanRedleg site scanUnmask Parasites site scanIf you find security weaknesses, take your site offline and fix them.  If you find that your site has been compromised, it's likely that you'll need to wipe the site and reload everything from a known-good backup.  See https://www.stopbadware.org/hacked-sites-resources for more resources.Protect your site against hacking. I suggest you review your site security and make sure it is well-protected against hacking, to prevent someone from breaking in and modifying it to serve malware.  See, e.g., https://www.stopbadware.org/prevent-badware-basics for some background.  Also make sure that your site software is fully updated.When I use these tools, here is what I find:Sucuri says you are running an outdated version of WordPress (pre-4.2).  It looks like you are running Wordpress 3.8.1; 4.2.2 is the current version.  This makes it likely that your site is vulnerable and can be compromised: there are multiple known vulnerabilities in Wordpress 3.8.1.  You should make sure to always run up-to-date versions of software.  When you fail to keep up-to-date, it creates an opportunity for attackers to compromise your site and use it to host malware.  So, upgrade WordPress.Google Safe Browsing says that your site was hosting malware when Google visited on 2015-05-10: 1 page(s) resulted in malicious software being downloaded and installed without user consent.  Apparently no malware was found on the latest visit, 2015-05-25, so it sounds like at some point in the past, your site was hosting malware, but it isn't any longer.It's not clear what the problematic page was.  The report for www.andreszsogon.com/grf-wizard says there were no malicious pages found under /grf-wizard.  So, you can infer that the problematic page must have been some other page under www.andreszsogon.com -- but it wasn't anything under /grf-wizard.  I tried playing around with Google Safe Browsing's online interface, but I wasn't able to narrow down which page caused your site to be listed in their system.