Clean the Trojan horse program in your own computer _ security related

Source: Internet
Author: User
Trojan Horse is a remote control based virus program, which is very hidden and harmful, it can control you or monitor your computer without your knowledge. Here is a talk about the Trojan often hiding places and cleaning methods.

First check if there is a trojan in your computer

1, integrated into the program

In fact Trojan is also a server-client program, in order not to allow users to easily delete it, it is often integrated into the program, once the user activates the Trojan, then the Trojan file and an application bundled together, and then uploaded to the server to cover the original file, so even if the trojan was deleted, As long as the application bundled with the Trojan, the Trojan will be installed up. Bound to an application, such as binding to a system file, every time Windows startup starts a Trojan.

2, hidden in the configuration file

Trojan is too cunning, know the rookie is usually using the graphical interface of the operating system, for those who have not very important configuration files are mostly indifferent, which just give a trojan to provide a hiding place. And the use of the special role of configuration files, Trojans can easily in everyone's computer run, attack, and thus peeping or watching everyone. However, now this way is not very covert, easy to find, so in Autoexec.bat and Config.sys loaded Trojan horse program is not seen, but also can not be taken lightly oh.

3, lurking in the Win.ini

Trojan Horse to achieve control or monitor the purpose of the computer, must run, however, no one will be silly to their own computer to run the damn Trojan. Of course, the Trojan is also early psychological preparation, know that human is a high IQ of animals, will not help it to work, so it must find a safe and can be in the system start automatically run the place, so lurking in the Win.ini is a Trojan feel more comfortable place. You may wish to open Win.ini to see, in its [Windows] field has the start command "load=" and "run=", in general, "=" after the blank, if there is followed by the program, for example: Run=c:\windows\file.exe Load=c:\windows\file.exe

At this time you must be careful, this file.exe is probably a Trojan oh.

4, camouflage in the ordinary document

This method appears late, but it is now very popular, for unskilled windows operators, it is easy to be fooled. The specific method is to disguise the executable file as a picture or text----in the program to change the icon to the Windows default Picture icon, and then change the file name to *.jpg.exe, because the Win98 default setting is "Do not display known file suffix name", the file will be displayed as *.jpg, People who don't pay attention to this icon is a Trojan horse (if you embed a picture in the program is more perfect).

5, built into the registry

The above method makes the Trojan really comfortable for a while, no one can find it, and can automatically run, it is fast! However, the long time, the human quickly took it out of the hand, and it was severely punished! But it is also unwilling, summed up the failure of the lesson, that the above hiding place is very easy to find, now must hide in not easy to find place, so it thought of the Registry! Indeed, due to the complexity of the registry, Trojans often like to hide in here merry, quickly check, what procedures in its next, open eyes carefully look, do not let go of the Trojan Oh: hkey_local_machine\software\microsoft\windows\ CurrentVersion all the key values that begin with "run"; hkey_current_user\software\microsoft\windows\currentversion all keys that start with "run" ; hkey-users\. Default\software\microsoft\windows\currentversion all the key values that begin with "run".

6, hiding in the System.ini

Trojan Horse is really everywhere! Where there is a loophole, where it is drilled! This is not, Windows installation directory under the System.ini is also a trojan like hidden place. Or be careful, open this file to see if it is different from the normal file, in the [boot] field of the file, is there such content, that is Shell=Explorer.exe File.exe, if there is such content, then you are unfortunate, because here File.exe is the Trojan server program! In addition, in the [386Enh] field in System.ini, be careful to check the "driver= path \ Program Name" In this paragraph, it may also be used by Trojans. Again, in the System.ini [mic], [drivers], [drivers32] These three fields, these sections are also played to load the role of the driver, but also add Trojan program good place, now you should know also to pay attention here.

7, invisible in the startup group

Sometimes the Trojans don't care about their whereabouts, it is more attention to the ability to automatically load into the system, because once the Trojan loaded into the system, any way you can not get rid of it (hey, this trojan skin is really too thick), so according to this logic, the Startup group is also a good place to hide the Trojan horse, Because this is really a good place to load and run automatically. The folder for the Move Group is: C:\windows\start Menu\Programs\Startup, location in the registry: hkey_current_user\software\microsoft\windows\ currentversion\
Explorer\shellfolders startup= "C:\windows\start Menu\Programs\Startup". Be careful to check the startup group often!

8, concealed in the Winstart.bat

According to the above logic theory, the Trojan can automatically load the place, the Trojans like to stay. It's not, Winstart.bat is also a file that can automatically be run by Windows, and is automatically generated in most cases for applications and windows, and starts after Win.com is executed and most drivers are loaded (this can be learned by pressing the F8 key at startup and then by selecting a step-by-step Start method to track the startup process). Because the function of Autoexec.bat can be replaced by Winstart.bat, the Trojan can be loaded and run as it is in Autoexec.bat.
9, bundled in the boot file

That is, the application startup configuration file, the control side use these files to start the program's characteristics, will be made with the Trojan Start command file upload to the service side of the same name file, so you can achieve the purpose of starting the Trojan horse.

10, set in the Super connection

Trojan owner placed malicious code on the Web page, luring users to click, the user clicks the result is self-evident: Kaimen! Don't just click on the link on the page, unless you know it, trust it, die for it, and so on.
Next look at the Trojan removal method

1, check the registry run, Runserveice, and other items, the first backup, note can start the address of the item, and then the suspicious deletion.

2, delete the above suspicious key in the hard drive of the execution file.

3, generally this kind of document in Winnt,system,system32 such folder, they generally will not exist alone, most likely there is a copy of the parent file, check C, D, E and other discs under the suspicious. exe,.com or. bat files, delete them.

4, check the registry HKEY_LOCAL_MACHINE and Hkey_current_user\software\microsoft\ Internet Explorer\Main several items (such as local Page), if modified, You can change it back.

5. Check Hkey_classes_root\inifile\shell\open\command and hkey_classes_root\txtfile\shell\open\ command, and so on, the default open programs for several common file types are changed. This must be changed back. A lot of viruses are modified by the default open program such as Txt,.ini to let the virus "live Forever, Never kill".

6, if possible, the virus of the parent file disassembly, such as my last virus, by using Ida disassembly, found that it also steals the system password and create%systemroot%\system\mapis32a.dll file to send the password to a mailbox, because I use the W2K , so it certainly didn't succeed.

At this point, the virus completely removed! I suggest the ability, always pay attention to the system changes, strange ports, suspicious processes and so on. Now the virus is not as before the system data damage is very serious, or found more, so try to antivirus (simpler virus, Trojan).
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