#COMPUTER VIRUSES

-Computer viruses are unwanted software programmes or pieces of code interfere with the functioning they spread through contaminated files, data, and insecure networks once it enters your system, it can replicate to produce copies of itself to spread from one program to another program and from one infected computer to another computer. so, we can say that it is a self-replicating computer program that interferes with the functioning of the computer by infecting files, data, programmes, etc.

First Computer Virus

-Brain the first personal computer virus, began infecting 5.2" floppy disk in 1986. As secure list reports, it was the work of two brothers, Basit and Amjad Farooq Alvi, who ran a computer store in Pakistan.

-Brain is the industry standard name for a computer virus that was releases in the first from 19 January 1986 and is considered to be the first computer virus for the IBM Personal Computer (IBM PC) and compatibles.

-The primary purpose of the virus was not to harm, but rather to protect the brothers' medical software from begin copied without their permission. However, the virus quickly spread widespread customer base and caused widespread damage. The virus was able to replicate itself and spread to other floppy disks, making it one of the first example of a self-replicating virus.

-The virus was relatively simple in design, but it was highly effective at propagating itself. The virus replaced the original boot sector of a floppy disk with its own code, which was designed to check for the presence of the virus on the system it was infecting. If the virus was not present, it would copy itself to the boot sector and then infect any other floppy disks that were used on the infected computer.

-Brain was also one of the first example of a "stealth" virus, meaning it was able to hide itself from detection by antivirus software. the virus was able to do this by intercepting and modifying the BIOS calls that were used to read the boot sector of a floppy disk. This made it difficult for antivirus software to detect the virus, as it appeared as though the original boot sector was still intact.

Symptoms of a computer virus

-Slow Computer Performance - The machine may work slowly e.g., It will take more time to open or shut down the computer or while opening a file document computer application, etc The operating system and internet speed may get slow.

-Frequent POP-UPS - A virus may cause unusual frequent pop-ups on your window.

-Hard drive Issue - The hard drive may exhibit unusual high activity even when it is not in use it may cause unwanted changes to your hard drive and may freeze or crash this device.

-Frequent Crashes - One may experience frequent sudden system crashes while playing games, watching videos, or doing some other work using games, infected system. A blue screen appears when it crashes.

-unknown Programmes - unwanted programmes may open or start automatically when you start your computer's list of active applications, sometimes, the window sheet down unexpectedly without any reason. 

-Usual Activities - Your machine may perform differently, such as you may not be able to log into your accounts to delete the corrupt files, and Blue Screen of Death (BSOD) may appear frequently, and more furthermore, the hardware, software, or OS may start malfunctioning leading to crashing the system abruptly.

The Future of Computer Viruses 

-For more than 60 years. Computer viruses have been part of collective human consciousness, however what was once simply cyber vandalism has turned quicky to cybercrime. Worms, Trojans and viruses are evolving. Hackers are motivated and clever, always willing push the boundaries of connection and code to devise new infection methods. The future of cybercrime seems to involve more POS (point of sale) hacks, and, perhaps, the recent Moker remote access Trojan is a good example of what's to come. This newly discovered malware is hard to detect, difficult to remove and bypasses all known defence. Nothing is certain change is the lifeblood of both attack and Défense.