VIRUSES + DESTRUCTIVE PROGRAMS = MALWARE Updated by J9Wise from ORIGINAL SOURCE: Stewart Hudnall / Jennifer Morgan

Malware can be a Nuisance or Destructive. Destructive malware can be serious by: Corrupting files Destroying data Corrupting entire computer systems Nuisance malware typically just displays irritating messages or otherwise gets in your way when you're trying to do something else. Malware can travel inside programs and applications that are installed on your computer, as email attachments, as downloadable programs and other files from the Internet, and hidden on hardware such as flash drives.

A Virus is a particular kind of malware program written to alter the way a computer operates without the permission or knowledge of the user. Similar to a flu virus, when computer viruses arrive on your computer, they often inject themselves into other benign software that it finds on your computer, adding some coded instructions inside existing instructions that allow the full virus program to go to work when you use one of your regular applications. To differentiate them from other malware, viruses typically only work after a user has run a program.

Some KNOWN Categories of Malware Worms Trojan Horse Rootkit/Bootsector Virus Bots/Droppers Logic Bombs/Time Bombs Ransomware/Scareware Spyware

Categories of Malware Worm: A program with a primary intent to replicate itself and execute some instructions on a computer, and then spread itself onto another computer and beyond. Its primary distinction from a virus is that a worm runs itself, while viruses typically require a user to run something else first that triggers the virus.

Categories of Malware Trojan/ Trojan Horse: Has the appearance of being a benign and useful program, but hidden inside is something undesirable that acts in secret. For example, you may think you're running a calculator application, but when you activate the calculator program, the Trojan virus inside also starts running something that you don't want.

Categories of Malware RootKit/Boot Sector Virus: A small program that attaches itself to the software used by a computer often during its startup process. The program alters common computer instructions, modifying the results of normal computer operations. Boot sector viruses are a subset of rootkit viruses as they attack the disk boot up software specifically. Once, these were particularly difficult to remove because operating systems prevented antivirus software from accessing the system startup programs, but now, most up-to-date cleaning software can take care of these easily, and modern operating systems make it hard for these kinds of viruses to remain around long enough to do any damage.

Categories of Malware Bots and Droppers: Programs that infest your computer hardware doing nothing at all while waiting for a signal from its owner. The signal will then cause all the computers with bots to execute some instructions at the same time. A dropper is a kind of bot that funnels malware of all kinds into the computer its on, and their owners can even charge for this service to creators of other malware. Spammers, for example, often use these to send junk emails from other computers so that their own computers won't be implicated.

Categories of Malware Logic Bombs/ Time Bombs: Another form of Bot that is programmed simply to initiate its actions on a specific date or when a specific event occurs. When the date passes, it deletes itself to eliminate tracing its source.

Categories of Malware Ransomware/Scareware: Malware programs that attack your computer or threaten to attack your computer that also demand a ransom (often in the form of a purchasable “cleaning service”) before you can rid yourself of the malware. Or they sell you a fake program that appears to work, but actually does nothing because their threat was also fake. This is the malware equivalent of the old “protection racket” that makes you pay somebody so you won't get harmed by the same people you've paid. Sadly, these are quite clever and are often hard to distinguish as legitimate.

Categories of Malware Spyware: Malware bots that search through your computer's files looking for stored passwords and usernames, and then forward that information back to the owner of the malware who can then use it for identity theft and other crimes. Sp yware can also be used to target advertising based on what it finds in your computer files.

SPREADING MALWARE Malware spreads from computer to computer when people distribute infected files by exchanging DVDs and CDs, sending e-mail attachments, and downloading files from a network or the Internet. When you open the infected file, virus malware activates and then prepares itself to infect the next program you run or disk you use. You may not even know your computer has the virus, thus making it easier to spread the virus. Malware can lurk in a computer for days or months, quietly replicating (copying) itself until removed.

How Malware Spreads Networks and the Internet: Phishing Schemes: A computer may be infected through a network which spreads from another computer connected to that same network. And since the Internet is simply a giant network of networks, it is often the primary source of malware attacks. Phishing Schemes: These schemes try to get your personal information through email messages pretending to be legitimate sites. When you visit these sites, malware can also be automatically installed on your computer.

Other Kinds of Attacks Dictionary Attacks use a targeted technique of successively trying all the words in an exhaustive list (dictionary) to figure out usernames and passwords on a computer system.

Other Kinds of Attacks War Driving is the act of driving around a neighborhood in a vehicle with a laptop computer, an antenna, and a wireless adapter trying to find and exploit existing wireless networks.

ADWARE Adware is the common name given to nuisance software that a user acquires with advertisements embedded into the application. A common variation on Adware occurs when installing a program, and additional programs are “offered” to be installed first. If you don't pay attention, you may end up permitting this software to install itself by blithely clicking [Next] during the installation process instead of unchecking the boxes that ask you if you want it in the first place.

PROTECTING YOUR COMPUTER Just as you protect yourself from illness and disease, you can cut the chances of your computer systems being infected with these actions: Install trusted anti-virus program and schedule it to perform regular scans Install an anti-malware program and use it regularly Never open email attachments without scanning them first with your anti-virus software Protect your downloads by using sites you can trust, and scan all downloads before opening them.

Protecting Your Computer From Malware Install security updates coming from your operating system's maker Monitor the actions of your computer for unusual behavior Use legitimate software sources Install a Firewall that always runs Be prepared to lock down in case of an attack Keep your password secure and classified.

Internet Controls for Safety Firewalls: Form a barrier between two networks that can only be crossed with approved credentials These can be software (part of the Operating Sytem) or hardware (often on routers) barriers. Filters: Control what can be viewed on Internet. These typically block certain domains or specific websites using a blacklist/whitelist system. Sites not on the blacklist, or specifically on the whitelist, can be allowed through the filter. Parental Control setting: Filtering software that allows control over kids' access to the Internet as well as specific apps.