Even though most of the Trojans are targeting computers that run on 32-bit CPUs, Trojan:Win64/Sirefef.D is a malware component of Win32/Sirefer rootkit aimed for the 64-bit CPUs. It has been observed that this Trojan generates fake traffic for a service that counts visitors in various websites. The address of the site that Trojan:Win64/Sirefef.D works for is liveinternet.ru. However, that is not all, because Trojan:Win64/Sirefef.D can also modify the search results in order to redirect the user to one or the other suspicious website.
When this Trojan is installed in the affected system, it adds a subkey in the registry and it allows Trojan:Win64/Sirefef.D to load automatically together with your Windows. Also, if you get Trojan:Win64/Sirefef.D that also means you already have other malware in your computer, because usually this Trojan is installed by other rootkit installers such as Backdoor:Win32/Smadow or Trojan:Win32/Sirefef.J. Since the Trojan is installed by rootkits, it might be lurking in the hidden folders, trying to avoid being detected by security products, and this secrecy makes the removal of Trojan:Win64/Sirefef.D even trickier.
Even though this Trojan is created mainly for generating fake traffic for one particular website that does not mean it is less dangerous. Keeping in mind that it is installed by rootkits, Trojan:Win64/Sirefef.D infection may open a way for other types of malware. Before you know it, your computer might be full of parasites, slowing your system down, stealing your personal data (such as your banking logins and passwords), and even making your computer into a source of infections for other computers.
Due to its cunning nature it might be hard to get rid of Trojan:Win64/Sirefef.D on your own, especially, as this program does not have a definite interface. However, if you notice that there is something odd about the way your computer operates, do not hesitate to acquire a legitimate security program that will perform a full system scan finding all of the malware related to the Trojan. Then you will be able to remove Trojan:Win64/Sirefef.D automatically and protect your system against similar attacks.