Virus

When a computer program copies itself and damages a computer it is termed as computer virus. It destroys the information in one’s computer. This infection is contagious and could spread to other computers. Malwares like computer worms, Trojan horses, root kits, spyware and adware could be different types of viral damages that a computer can encounter. While worm attacks the vulnerable aspects of the security system, Trojan horse appears to be harmless and does the damage. These viruses were initially made in removable media like floppy disk for instance. The concept of computer viruses became popular in 1980s. Macro Viruses which used scripting languages became popular in 1990s. When a computer has been attacked by viral elements it is best to stop using the computer until it is reinstalled. Pirated software is another source of these damaging elements. 

Types of Viral damages

Virus could blend with the executable files and pose as a legitimate program. These damages could be resident virus or nonresident virus. Resident virus loads itself in the memory and transfers to the host. Resident virus could be classified as slow infectors and fast infectors. Nonresident virus on the other hand searches host, infects the target and transfers to application program. Nonresident virus contains finder module and replication module.

Methods of Infection

Viral damages like spyware collect information about the user. Adware enters through advertisement software. Virus could accompany emails in the form of attachments. Viral damages could also be done in the form of web address links. Cross site scripting is another form by which viral attacks occur. Attacks are made through executable files, volume boot records, general purpose script files and shell script files, system specific auto run script files, arbitrary computer files and PDF or HTML links.

Virus Removal Tools

Virus is detected and prevented by Antivirus software. A signature based viral detection is done with the help of executable codes. Those viral damages that are unique without any signature trait could be dealt with zero day threats and heuristics. Heuristic algorithm is a method used to detect virus based on their behavior. When a file goes through the sand box test malicious actions could be detected. Many of the simple virus removal tools are found in free online sites. These removal tools search for signatures, executable programs, applications and email clients.

Computer shows certain signs like running slowly, frequently getting crashed, displaying distorted menus and dialog boxes which hint the user that his computer is being attacked.

Questions:

• What are the methods of Virus attacks on your computer?
• What are the signs that your computer displays when attacked by virus?