Antivirus1.descargar.es is an unreliable website that may show a fraudulent pop-up alert on the computer system while computer users are surfing the Internet. The bogus pop-up notification of Antivirus1.descargar.es may be displayed by adware that may propagate and invade the computer system while PC users are downloading freeware from unidentified download websites. The tricky pop-up warning message shown on Antivirus1.descargar.es may urge the computer user to download a plug-in for Windows XP, Vista, 7 + 8. In fact, this warning message is not related to the computer user's OS. The fake Antivirus1.descargar.es alert was produced to probably disperse adware and other potentially unwanted programs (PUPs). When the computer user clicks on the 'Free Download Safe Download' green button in the pop-up warning message of Antivirus1.descargar.es thinking that he will receive a plug-in, he may, in truth, agree to install adware or a potentially unwanted application.