Symptoms of Trojan virus in computer

The symptoms of Trojan viruses in computers are: 1. Files or folders disappear for no reason; 2. No response when running applications; 3. Computer startup items contain suspicious startup items; 4. Computer runs extremely slowly; 5. , The anti-virus software fails; 6. The computer runs abnormally; 7. The system language is changed to other languages; 8. The blue screen is black; 9. The homepage is tampered with, etc.

The operating environment of this article: Windows 7 system, Dell G3 computer.

Symptoms of Trojan viruses in computers

(1) Files or folders disappear for no reason:

When some files or folders are found in the computer If it disappears for no reason, you can be sure that the computer has been infected with a virus. Some computer viruses hide files or folders, then forge the hidden files or folders and generate executable files. When users click on such disguised files with virus programs, they will directly cause the virus to run, causing the user to Disclosure of information.

(2) No response when running the application:

Some computer viruses use image hijacking technology to change the running path of commonly used applications to the virus running directory, so that when we try to run normal program, it actually runs a virus program, causing the computer virus to start.

(3) Computer startup items contain suspicious startup items:

Check the "System Configuration Implementation Program" window. If you find an unknown executable directory, you can be sure that your computer has been infected. It's a virus. Of course, more often virus programs use modified registry entries to add self-starting entries.

(4) The computer runs extremely slowly:

When the computer runs obviously slowly, it may be caused by a virus in the computer. Computers infected with viruses will continue to run in the background through virus programs, and most viruses will occupy too much CPU and memory, and most Trojan viruses will use the Internet to spread users' private information.

(5) Anti-virus software failure:

Anti-virus software is used to protect the system. Therefore, when the anti-virus software cannot run normally for anti-virus operations, you can be sure that the computer has been infected with a virus. This Sometimes we need to use the Internet to perform online anti-virus operations. Most security protection software, such as 360, Kingsoft Guardian, and QQ Manager, the three more mainstream domestic security protection software, have independent defense modules. The first thing viruses or Trojans attack is the independent defense module of the security protection software. If you find that the active defense module is turned off or the security protection software cannot be started directly or there is a memory error, it is very likely that the security protection software cannot withstand this powerful virus and is paralyzed

(6) Abnormal computer operation:

Viruses can take up too much system performance, cause file damage, and even seriously affect system stability. When your computer has an unexplained blue screen, runs programs abnormally, runs too slowly, or has a large number of suspicious background running programs, you need to pay attention. The computer may be infected with a virus.

(7) Change the system language to other languages

Your computer system language defaults to Simplified Chinese. If you find that the system language of Jiji Aji has been changed to other languages ​​after booting, it is very likely that the system language has been changed to other languages. If you are infected by a malicious virus, you can use security protection software to scan and remove the virus

(8) Blue screen and black screen

Black screen is relatively rare, but blue screen is more common. If you are infected by an inexplicable malicious virus, your computer may suddenly blue screen when running a certain game or software. The blue screen code may be a common code, which may mean that the computer automatically and forcefully restarts to protect the system.

(9) Tampering with the homepage, forcibly refreshing or redirecting the webpage, and frequently popping up advertisements

Tampering with the homepage is the main target of early viruses. After the computer operating system is poisoned, the browser homepage usually occurs. The phenomenon of tampering, so IE Companion, a small software that repairs homepage tampering, was quite popular back then. If the browser page keeps loading/refreshing repeatedly or advertisements pop up for no reason at the same time, then it is likely to be poisoned

(10) The application icon is tampered with or blank

Computer If the program shortcut icon on the desktop or the icon of the main exe file in the program directory has been tampered with or is blank, then it is very likely that the exe program of this software is infected by a virus or Trojan horse. Worms will carry out such infection modifications

Simple ways to deal with viruses in computers

1. Users who are surfing the Internet should disconnect immediately if they find an abnormality

If You find that IE often asks you whether to run certain ACTIVEX controls, or generates inexplicable files, or asks about debugging scripts, etc. You must be vigilant, you may have been tricked. There are two typical cases of Internet intrusion: 1. When browsing some web pages with malicious code, the default homepage or title of the browser is modified, which is considered light; Can you format the hard drive or keep your windows open until it runs out of resources and crashes? This situation is much worse. Your unsaved and already placed data on the hard drive may be partially or completely lost.

　2. It is a potential Trojan horse attack by hackers, or a worm-like virus attack, which allows your machine to continuously send your privacy to the outside world, or uses your name and email address to send spam to further spread the virus; and There are manual intrusions by hackers, snooping into your privacy or deleting and destroying your files.

Solution: Disconnect immediately. This will reduce your own losses and prevent the virus from spreading to more online computers.

2. After being poisoned, you should immediately back up and transfer documents, emails, etc.

After being poisoned, it is easy to run anti-virus software to clean it, but in order to prevent the anti-virus software from accidentally killing or deleting it, you still have to After processing documents and important emails, you should first transfer and back them up to other storage media. Some files with long file names and unprocessed emails require backup under Windows, so the first point here is that the author recommends that you do not exit Windows because once the virus attacks, you may not be able to enter Windows.

Regardless of whether these files are poisonous or not, you should back them up and mark them for investigation with a label. Because some viruses are specifically designed for a certain anti-virus software and will destroy other files as soon as they are run, backing up first is a precautionary measure. After you clear the virus from your hard drive, it would be more appropriate to slowly analyze and process these additional backup files.

3. You need to run the software to kill CIH under Windows first (even in a virus-contaminated environment)

If you find a CIH virus, be careful not to follow the recommendations in newspapers and manuals. The first step is to shut down the machine, cold-start, use the system disk to boot, and then kill the virus. You should also run the software specifically designed to kill CIH in a virus-containing environment. If you do this, the anti-virus software may report that some files cannot be cleaned due to read-write protection, but the actual purpose of running with the virus is not to completely remove the virus, but to minimize the damage when the CIH is turned on next time to prevent it. If you damage the motherboard's BIOS hardware by turning on the computer again, the screen will go black, making it impossible to carry out the next step of anti-virus.

4. Clean DOS boot disk and DOS boot disk are required for anti-virus

By now, you should follow the standard manuals of many anti-virus software to do it step by step, that is, shut down and cold start , it is indispensable to boot with a clean DOS boot disk; in addition, because Windows may have destroyed some key files after being poisoned, and frequent illegal operations will occur, so the anti-virus software under Windows may not be able to run. So please also prepare an anti-virus software under DOS just in case.

Even if you can run anti-virus software under Windows, please use two or more tools for cross-cleaning. In most cases, Windows may need to be reinstalled because viruses can destroy some files and slow down the system or cause frequent illegal operations. For example, even if CIH is killed, Microsoft's Outlook email program still responds slowly. It is recommended not to be biased against a certain type of anti-virus software. Due to the different focus during development and the use of different anti-virus engines, various anti-virus software have their own strengths and weaknesses, and the cross-use effect is ideal.

5. If you have a backup of Ghost, partition table, and boot area, it is safest to use it to restore it once.

If you have made a Ghost backup of Windows in normal times, use it to mirror it once. The operating system you get is the safest. In this way, even the potential unkilled Trojan programs are also cleaned up. Of course, this requires that your GHOST backup is absolutely reliable. Haha, if you "back up" the Trojans when you create Ghost...

Six. After restoring the system again, change your network-related passwords

Including the username and password for logging into the network, the password for your email and QQ, etc. to prevent hackers from knowing you during the last intrusion. password. Also because many worm attacks randomly send out your messages, appropriate changes are necessary.

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