For FirefoxPortableESR_52.6.0_Russian.paf.exe Comodo antivirus shows the file is infected with TrojWare.Win32.Backdoor.Tovkater.
For recently posted on your site FirefoxPortableESR_52.6.0_Russian.paf.exe Comodo antivirus shows the file is infected with TrojWare.Win32.Backdoor.Tovkater.ID