What are the most dangerous computer viruses?

There are many different types of computer viruses out there, and new ones are being created all the time. Some of the most dangerous computer viruses include:

1. The ILOVEYOU virus: This virus was first released in 2000 and quickly spread around the world, causing billions of dollars in damage. The virus would infect a computer and then send itself out to all of the victim’s contacts in an email that appeared to be from a friend or loved one. The email would say “ILOVEYOU” and would have an attachment that, when opened, would install the virus on the recipient’s computer.

2. The Melissa virus: This virus was released in 1999 and was similar to the ILOVEYOU virus in that it would spread via email. However, the email would contain a password that, when entered, would allow the virus to gain access to the victim’s Microsoft Word documents and password-protected websites. The virus would then replicate itself and send itself out to all of the victim’s contacts.

3. The CodeRed virus: This virus first appeared in 2001 and was particularly dangerous because it was able to spread quickly and infect entire networks of computers. The virus would exploit a security hole in Microsoft’s Internet Information Server software and then create a “backdoor” on the infected computer, allowing the attacker to gain remote access. From there, the attacker could install additional software, including viruses, on the victim’s computer.

4. The Conficker virus: This virus was first released in 2008 and is still active today. It is estimated to have infected millions of computers around the world. The virus spreads via network shares and removable media and is particularly difficult to remove once it has infected a computer. The virus can be used to remotely control the victim’s computer and has been used to launch attacks on other computers.

5. The Stuxnet virus: This virus was first discovered in 2010 and is believed to have been created by the United States and Israel to attack Iran’s nuclear facilities. The virus is sophisticated and was able to spread via network shares and USB drives. Once it infected a computer, it would look for specific industrial control systems and then modify the system’s settings, causing physical damage to the equipment.

These are just a few of the most dangerous computer viruses out there. New viruses are being created all the time, so it’s important to have up-to-date anti-virus software installed on your computer and to be careful about clicking on links or opening attachments from unknown sources.

What are the most common types of computer viruses?

A virus is a code which has potential to copy itself and corrupt system. There are following types of computer viruses −

Boot sector viruses − These viruses infect boot sector of hard disk or floppy. When system starts, it infects the system. Boot sector viruses are very difficult to remove and detect. Some examples of boot sector viruses are −

∙ directories on your hard disk. When you double click on these shortcuts, the virus gets activated from the root directory and infects system files.

A directory may also get dropped by some other virus which may open a door for this virus.

∙ The viruses which come as an email attachment and get executed as soon as you open that email.

∙ Viruses might also come bundled with some other software which you might download from internet.

Macro viruses − These viruses are written in macro language which is used by some applications like MS-Word, MS-Excel etc. When you open a document infected by macro virus, the virus gets executed and infects system files.

File infector viruses − As name suggests, these viruses infect executable files. When you try to run an infected program, the virus gets executed and infects system files. Some examples of file infector viruses are −

∙ We cannot directly execute a .doc or .xls file. These files first need to be open by their respective programs (MS Word or MS Excel). So these viruses first infect MS Word or MS Excel program files and then infect .doc or .xls files.

∙ Some viruses infect .exe files. When we try to execute an infected .exe file, the virus gets executed and infects system files.

System or program viruses − These viruses infect system files or program files. If system files get infected, the virus gets executed as soon as system starts. If program files get infected, the virus gets executed as soon as that program is run.

Some examples of system or program viruses are −

∙ lpt$vxd, wininit.exe, io.sys etc.

Multipartite viruses − These viruses infect both boot sector as well as system or program files. So they are difficult to detect and remove.

Memory resident viruses − These viruses install themselves in memory and whenever an infected file is executed, the virus gets executed and infects system files. Some examples of memory resident viruses are −

∙ CMJ, mentor, tequila etc.

Overwrite viruses − These viruses directly overwrite data present in system files and make those files corrupt. When we try to open those files, a message is displayed saying that file is corrupted.

Some examples of overwrite viruses are −

∙ Way, trj.Reboot, trip etc.

Web script viruses − These viruses infected web pages present on internet. When we try to open an infected webpage, the virus gets executed on our system.

android viruses

There are different types of computer viruses but the most common ones are the following:

boot sector viruses,

macro viruses,

file infector viruses,

system or program viruses,

memory resident viruses,

overwrite viruses, and

web script viruses.

Visit malwarezero.org to learn more about most dangerous pc viruses. Disclaimer: We used this website as a reference for this blog post.