47. Viruses

Computer Virus

Malicious code that’s run on a machine without the user’s knowledge and this allows the code to infect the computer whenever it has been run

Virus Types

Boot Sector

Macro

Program

Multipartite

Encrypted

Polymorphic

Metamorphic

Stealth

Armor

Hoax

Boot Sector Virus

Stored in the first sector of a hard drive and is then loaded into memory whenever the computer boots up

Macro Virus

A form of code that allows a virus to be embedded inside another document so that when that document is opened by the user, the virus is executed

Program Virus

Tries to find executables or application files to infect with their malicious code

Multipartite Virus

A combination of a boot sector type virus and a program virus

Encrypted Virus

Designed to hide itself from being detected by encrypting its malicious code or payloads to avoid detection by any antivirus software

Polymorphic Virus

Advanced version of an encrypted virus, but instead of just encrypting the contents, it will actually change the virus’s code each time it is executed by altering the decryption module in order for it to evade detection

Metamorphic Virus

Able to rewrite itself entirely before it attempts to infect a given file

Stealth Virus

Not necessarily a specific type of virus as much as it is a technique used to prevent the virus from being detected by the anti-virus software

Armor Virus

Have a layer of protection to confuse a program or a person who’s trying to analyze it

Hoax

A form of technical social engineering that tempts to scare end users into taking undesirable action on their system