Computer virus

PC virus

Are you fedup with certain types of  problem facing in your computer due attack of a malicious virus??Then you are in the right place.In this article ,i will explain about you the Viruses present in your PC and how does this types of viruses is entering to your computer. i will also give you some tips to prevent viruses entering to computer.

First of all lets understand ;

what is virus in your computer?
A virus is  piece of code which is capable of copying itself and typically has a detrimental effect, such as corrupting the system or destroying data.The virus requires someone to knowingly or unknowingly spread the infection without the knowledge or permission of a user or system administrator.
A computer virus is a type of malicious software program ("malware") that, when executed, replicates itself by modifying other computer programs and inserting its own code.When this replication succeeds,the affected areas are then said to be "infected" with a computer virus.
Some computer viruses are programmed to harm your computer by damaging programs, deleting files, or reformatting the hard drive. Others simply replicate themselves or flood a network with traffic, making it impossible to perform any internet activity. Even less harmful computer viruses can significantly disrupt your system’s performance, sapping computer memory and causing frequent computer crashes.


Symptoms of a computer virus?

1. Slow computer performance
2. Erratic computer behavior
3. Unexplained data loss
4. Frequent computer crashes

What are types of Virus?

 1. Boot Sector Virus.

A boot sector virus is a type of virus that infects the boot sector of floppy disks or the Master Boot Record (MBR) of hard disks (some infect the boot sector of the hard disk instead of the MBR).From a user perspective, boot sector viruses are some of the most dangerous. Because they infect the master boot record, they are notoriously difficult to remove, often requiring a full system format. This is especially true if the virus has encrypted the boot sector or excessively damaged the code.They typically spread via removable media. They reached a peak in the 1990s when floppy disks were the norm, but you can still find them on USB drives and in email attachments. Luckily, improvements in BIOS architecture have reduced their prevalence in the last few years.

2. Direct Action Virus

A direct action virus is a virus that attacks or start to work immediately this can include nonviolent and less often violent activities which target persons, groups, or property deemed offensive to the direct action participants.

It works by attaching itself to a particular type of file (typically EXE or COM files). When someone executes the file, it springs into life, looking for other similar files in the directory for it to spread to.

3. Multipartite Virus

A multipartite virus is a computer virus that infects and spreads in multiple ways. The term was coined to describe the first viruses that included DOS executable files and PC BIOS boot sector virus code, where both parts are viral themselves.

They can simultaneously infect both the boot sector and executable files, allowing them to act quickly and spread rapidly.

The two-pronged attack makes them tough to remove. Even if you clean a machine’s program files, if the virus remains in the boot sector, it will immediately reproduce once you turn on the computer again.

The multipartite viruses are often tricky and hard to eliminate. When all infected files have been cleaned, but the virus remains in the boot sector, files on the system will be infected again. Similarly, if the boot sectors were disinfected, but the files were still infected, then the boot sector will be re-infected.So be carefull of this types of viruses.

4. Polymorphic Virus

According to Symantec, polymorphic viruses are one of the most difficult to detect for an anti-virus program. It claims anti-virus firms need to “spend days or months creating the detection routines needed to catch a single polymorphic”.

But why are they so hard to protect against? The clue is in the name. Anti-virus software can only blacklist one variant of a virus – but a polymorphic virus changes its signature (binary pattern) every time it replicates. To an anti-virus program, it looks like an entirely different piece of software, and can, therefore, elude the blacklist.

5. OverWirte Virus

An overwriting virus is a malicious program which, after infection, will effectively destroy the original program code, typically by overwriting data in the system's memory.

Overwrite viruses typically have low visibility and are spread via email, making them hard to identify for an average PC user. They enjoyed a heyday in the early 2000s with Windows 2000 and Windows NT, but you can still find them in the wild.

6. spacefiller virus

A spacefiller (cavity) virus, on the other hand, attempts to be clever. Some program files, for a variety of reasons, have empty space inside of them. This empty space can be used to house virus code. A spacefiller virus attempts to install itself in this empty space while not damaging the actual program itself. An advantage of this is that the virus then does not increase the length of the program and can avoid the need for some stealth techniques. The Lehigh virus was an early example of a spacefiller virus.

Because of the difficulty of writing this type of virus and the limited number of possible hosts, cavity viruses are rare…however… A new Windows file format known as Portable Executable (PE) is designed to make loading and running programs faster. While a great goal, the implementation has the effect of leaving potentially large gaps in the program file. A cavity (spacefiller) virus can find these gaps and insert itself into them. The CIH virus family takes advantage of this new file format.

Fortunate,this type of virus is relatively rare, though the growth of Windows Portable Executable files is giving them a new lease of life.

7.Network Virus

Network viruses rapidly spread through a Local Network Area (LAN), and sometimes throughout the internet. Generally, network viruses multiply through shared resources, i.e., shared drives and folders. When the virus infects a computer, it searches through the network to attack its new potential prey. When the virus finishes infecting that computer, it moves on to the next and the cycle repeats itself.

8.FAT Virus

The file allocation table or FAT is the part of a disk used to connect information and is a vital part of the normal functioning of the computer. 

This type of virus attack can be especially dangerous, by preventing access to certain sections of the disk where important files are stored. Damage caused can result in information losses from individual files or even entire directories.

"There is more this types of virus is available over internet but its not possible to know  there working or how does they effect your PC.If i found more information about the viruses i will upload about it soon."

Now the question is:

How to protect your Pc from viruses?

This is what i personally do to protect my computers against viruses, malicious dialers and spywares:-

1. Install and Keep your Antivirus software up to date.
2. Don’t click on links within emails.
3. Back up your computer.(in case your PC Corrrupted).
4. Use a firewall *(Recommended).
5. Use pop-up blocker and adjust your User Account Control.
6. Create strong passwords.
7. Run Regularly Scheduled Scans with Your Anti-Virus Software.
8. Deploy DNS protection.
9. Disable autorun of anytpye of application currently running.
10. Don’t Use Open Wi-Fi.*(very Important).