Sad Trojan

Although this spyware is quite old and many modern computers are immune to its activities, the Sad Trojan is still able to make a lot of troubles for those users, who possess old operating computers. By using its special stealth algorithms, this spyware sneaks into the computer and starts installing many hostile applications on the machine. These applications are also parasitic, that's why it's tremendously important to keep your antiviral software updated in order to prevent Sad Trojan from infecting your computer.