What are the symptoms of computer poisoning?
When people are sick, they will have all kinds of symptoms. Similarly, when computers are poisoned, there will be some toxic reactions. If your computer has the following symptoms, you should quickly check it with antivirus software.
1. Frequent crashes;
2. The file can’t be opened;
3. Often report insufficient memory;
4. Prompt that the remaining space on the hard disk is insufficient;
5. A large number of documents of unknown origin appear;
6. Unreasonable loss of data;
7. The system runs slowly;
8. The operating system automatically performs the operation.
Second, Trojan virus
Everyone must have heard of Trojan virus, but what is Trojan virus?
(A) Trojan virus
Trojan horse virus refers to controlling another computer through a specific program (Trojan horse program). Trojan horse usually has two executable programs: one is the control end and the other is the controlled end. The name Trojan comes from the ancient Greek legend (the story of wooden horse in Homer’s epic, and the word Trojan means "Trojan", which means Trojan horse, that is, the story of wooden horse). Trojan horse program is a popular virus file at present. Unlike common viruses, it does not reproduce itself, nor does it "deliberately" infect other files. It attracts users to download and execute by disguising itself, and provides the Trojan horse breeder with a portal to open the seeded host, so that the breeder can destroy and steal the seeded file at will, and even remotely control the seeded host. The emergence of Trojan virus seriously endangers the safe operation of modern networks.
(2) Types of Trojan viruses
Trojan horse is not a horse, but it also has different varieties. Let’s take a note to introduce some common variants of Trojan horse.
1. Online Trojan Horse
Online game Trojans usually obtain users’ passwords and account numbers by recording users’ keyboard input, Hook game progress and API functions. The stolen information is usually sent to the Trojan author by sending an email or submitting it to a remote script program.
The types and quantity of online game Trojans are second to none in domestic Trojan viruses. Popular online games are all threatened by online trojan horses. After a new game is officially released, a corresponding Trojan horse program will be produced within one to two weeks. The public sale of a large number of Trojan horse generators and hacker websites is also one of the reasons for the proliferation of online game Trojans.
2. Online banking Trojan horse
The online banking Trojan is a Trojan virus written for the online trading system, and its purpose is to steal the user’s card number, password and even security certificate. Although the number of such Trojans is not comparable to that of online games, its harm is more direct and the losses of the victims are even heavier. Online banking Trojans are usually targeted. Trojan authors may first carefully analyze the online trading system of a bank, and then write virus programs for weak security links. In 2013, the security software computer housekeeper intercepted the latest variant of the online banking Trojan "Bomawen", and the Bomawen virus can modify the payment interface without trace, making it impossible for users to detect it. The fake QVOD download address provided by bad websites is widely spread. When users download and install this horse-hanging player file, they will fall into a Trojan horse. After the virus runs, it will start to monitor users’ online transactions, block balance payment and fast payment, force users to use online banking, and take the opportunity to tamper with orders and steal property.
With the popularity of online transactions in China, the number of users threatened by foreign online banking Trojans is increasing.
3.FTP Trojan horse
FTP Trojan opens port 21 of the controlled computer (the default port used by FTP), so that everyone can directly connect to the controlled computer through an FTP client program without a password, and can upload and download with the highest authority to steal the confidential files of the victim. The new FTP Trojan also adds a password function, so that only the attacker can know the correct password and enter the other computer.
(C) the harm of Trojan virus
The Greeks captured the gates of Troy with a big Trojan horse, and hackers will use Trojan horse programs to break through your computer full of loopholes, causing all kinds of harm.
1. Stealing our online game account, which threatens the security of our virtual property, will steal our online game account. After stealing the account, the game equipment in the account will be transferred immediately, and then the Trojan virus user will sell these stolen game equipment and game coins to make a profit.
2. The security Trojan that steals our online banking information and threatens our real property steals our online banking account number and password by means of keyboard recording and sends them to hackers, which directly leads to economic losses.
3. Use instant messaging software to steal our identities and spread bad information such as Trojan horses.
The computer infected with Trojan virus will download the program specified by the virus author, which has uncertain harm, such as paralyzing the computer.
Third, how to prevent Trojan virus and other virus attacks?
In order not to be defeated by the Greek Trojan like the Trojans, we need to do this:
1. Install anti-virus software for the computer, scan the system regularly and kill viruses; Update virus database and system patch in time;
TIP: The programming is not perfect, so there will inevitably be bugs in the software, and patches are specially used to fix these bugs. Because the original released software has defects, a small program is compiled to improve it after it is discovered. This small program is commonly known as patch. Regular patch upgrade to the latest security patch can effectively prevent illegal intrusion.
2. When downloading software, try to go to the official website or large-scale software download website, and disinfect before installing or opening software or files of unknown origin;
3. Don’t open links to unknown web pages at will, especially links to bad websites. When strangers send links to themselves through QQ, try not to open them;
4. When using the network communication tool, you don’t casually receive files from strangers. If you do, you can cancel the function of "Hide extensions of known file types" in "Folder Options" in the tool menu bar to view file types;
5. Strengthen the authority management of public disk space and regularly kill viruses;
6. Check with anti-virus software before opening the mobile storage, and a folder named "autorun.inf" can be established in mobile storage (to prevent the U disk virus from starting);
7. When it is necessary to download materials from public networks such as the Internet and transfer them to intranet computers, it is necessary to realize the transfer by burning CDs;
8. Set passwords for all accounts in the computer system, and delete or disable expired accounts in time;
9. Back it up regularly so that it can be repaired quickly after being seriously damaged by the virus.