Is your computer acting strangely, responding slowly, or doing things you don’t want it to do? If so, your computer may be infected by malware.
Malware, shorthand for malicious software, is computer software written for the purpose of disrupting the operation of a large number of computers, of accessing computers that normally cannot be accessed, or of stealing private information. These programs come in several forms: viruses, worms, spyware, adware, rootkits, backdoors, or Trojan horses. There is a lot of money in creating and disseminating these types of programs and hackers are coming up with new programs on a daily basis. If one does not protect one’s computer against these contaminations, one runs the risk of having private and financial information stolen by international thugs. The primary method of malware spread is via the Internet.
Types of Malware
Viruses: The most well-known piece of malware is the computer virus. This program can infect your computer and actually proliferate. Like the biological viruses, a computer virus can replicate itself within the host computer and then break out where it is sent to a large number of computers connected to the host computer. This type of malware only runs when a program is actively executed.
Worms: These programs are written to actively spread themselves automatically over any type of network, regardless of whether any executable has been run or not.
Spyware: Spyware is downloaded onto your computer and collects information without the user of the computer knowing it is doing so. Often spyware is in the form of a keylogger which logs every keystroke of the computer user. This is especially dangerous because a keylogger can tip off whoever is receiving the information to passwords, credit card numbers, bank account numbers, or other sensitive information. Sometimes spyware is used in corporations to maintain the integrity of their employees.
Adware: Adware is software that initiates advertisements such as popups on a user’s computer. Much adware is innocuous (although annoying), but some adware can contain internal programs which insert keyloggers or other malicious software onto a user’s computer.
Rootkits: In order for much of the malware to function without the knowledge of the computer user, it must somehow be hidden from the user. This is done by modifying the operating system of the computer such that the computer cannot see the malware process that is running. These small extra programs called rootkits are installed at the same time as the malware. Sometimes rootkits will disallow the use of anti-viral software altogether.
Backdoors: If a system has already been cracked by hackers, hackers can install a backdoor which is a way of getting into the computer or system without having to go through normal authentication. Backdoors allow easy access and an easy way to install malware.
Trojan horses: These are malicious programs that are disguised as programs that a user would normally want to or need to use. Typically these are bundled with legitimate software and so the user willingly installs it onto their computer. Often Trojan horses do not cause havoc immediately but wait to disseminate their malicious code.