There are many varieties of computer viruses. Some are only part of the program, others themselves are complete and useful applications. The Trojan also belongs to this type. As a rule, it is intended for implementation in a computer system. Once introduced, the trojan either sends information to the criminal from the infected computer, or destroys the system from the inside and uses it as a “crime tool”. A vivid example of such a virus can be called the program waterfalls.scr, which masquerades as a screensaver.
The Trojan program was named after the well-known wooden horse, with which the Greeks captured and destroyed the impregnable Troy. Like the Trojan horse, the eponymous program looks like a harmless and useful gift, but in fact it turns out to be an insidious surprise virus. Prior to installation, it is almost impossible to recognize such a virus. Some Trojans, even after installation, continue to perform the functions of the program under which they were disguised. Such a virus cannot multiply, but by launching it, the user resumes destructive activity every time in his computer. Almost all viruses of this type consist of a client and a server. The server is introduced into the infected system, and the client is used by a criminal
om to control it.
The Trojan has six types of malicious activity. Some viruses open remote access to the criminal, others simply destroy data, download additional pests, copy “fake” links to sites with paid registration, disable antiviruses and carry out DDoS attacks. If the infected computer is connected to the modem Internet, the trojan makes phone calls, after which the user’s account “loses weight” by a significant amount.
Trojan programs and protection against them
There are several signs by which infection with a trojan is determined. First of all, you need to pay attention to the startup registry. The “unauthorized” program that appears there may turn out to be a virus. An infection is also indicated by an unexpected download of games, applications or videos by the user, as well as arbitrary screenshots. In the process of starting the virus, the computer may reboot itself.
The Trojan can start viewing videos or images, open and close the drive console, or arbitrarily
turn off the computer.Due to the abundance of forms and types, there is no single way to combat the Trojan. If the system becomes infected, you should clear the folder with temporary Internet files, and then scan the system with antivirus. If the object detected by the antivirus is not deleted or cleared, you can find and delete it manually. But with a total infection, only reinstalling the operating system will help.
One of the newest viruses is called Qhost. This type of Trojan is a modified Windows file of 2600 bytes in size. The new virus blocks the user’s transition to certain sites and requests to selected servers. The blocking is carried out by adding a list of "forbidden" sites to the Trojan file named host. To neutralize such a virus, just edit this file in Notepad, and then scan the system with an antivirus program.