Types of Malicious Software
By Stephen Bucaro
Malicious software, commonly referred to as "malware" is a term that refers to any software
designed to gain access to and use without the owner's knowledge, or cause damage to a computer
or a computer network. The various types of malware include adware, spyware, viruses, and rootkits.
Adware is software that displays annoying popup ads and advertising banners. Adware
is frequently is bundled with free software that a user might feel is useful. The user doesn't
completely read the EULA (End User License Agreement) when installing the free software, so
they inadvertently agree to installing adware. While adware usually doesn't cause permanent
damage to a system, it can be annoying and can degrade the performance.
Spyware is software that monitors a users action while using a computer. when
the computer is online the spyware sends the information it gathers to the hackers that created
it. Sometimes the hackers sell this information for use by marketers. Some types of spayware
log keystrokes in order to capture usernames, passwords, and credit card numbers which they
either use for theft themselves, or sell online for other hackers to use.
Again, spyware can be bundled with free software, and when the user doesn't completely
read the EULA when installing the free software, they inadvertently agree to install the spayware.
While spyware may not cause permanent damage to a system, it can cause damage to a persons
finances and credit when used for identity theft.
A Virus is a program who's main purpose, similar to a biological virus, is to
make copies of itself and to spread those copies to other systems. Sometimes a virus is not
intentionally designed to cause damage, but as it spreads itself across the network it can
cause serious performance problems. Other viruses are designed to move or delete data from
a system. Some viruses are designed to cause damage by modifying or deleting operating system
A Worm is a type of virus that, unlike a usual virus which requires human interaction
to spread from system to system, has the ability to replicate itself and spread from system
to system on it's own without human interaction. One common method for a worm to replicate
and spread is to access an e-mail address book on the system and to send itself to everyone
on the list, accessing the address books on those systems and sending itself to everyone on
those lists, and so on. As the worm sends hundreds of thousands of copies of itself, it can
cause performance problems over the entire Internet.
About 1200 B.C. after a fruitless 10-year siege on the city of Troy, the Greeks constructed
a huge wooden horse, and hid a few soldiers inside. They then left, leaving the horse behind.
The Trojans, seeing that the Greeks had left, pulled the horse into the city. That night the
soldiers crept out of the horse and opened the gates for the rest of the Greek army who entered
and destroyed the city.
A Trojan Horse is type of virus that presents itself as a piece of useful legitimate
software, but much like the Greeks wooden horse, when installed and executed, it actually
does damage to the computer. Unlike a regular virus, a Trojan Horse (sometimes referred to
as just a "trojan"), does not replicate itself. Like a regular virus a Trojan Horse can move or
delete data, or cause damage by modifying or deleting operating system files.
Ransomware is malware that is downloaded to your computer. The ransomware encrypts
files on your computer, including critcal business files or your precious family photos and videos.
Encryption involves using a huge randomly generated number, called a key, to encode the binary
data of which a file is made. You can't restore the file without the key. And since the key is
such a huge random number, nobody, except the ransomware criminals and maybe the National Security
Agency, has the ability to recreate the key and decrypt your files.
You'll receive an email or a window pops up informing you that if you fail to pay a ransom of
from several hundred to several hundred thousands of dollars, the key to decrypt your files will
be destroyed. In order to pay the ransom you'll need to convert your money to Bitcoin, an untraceable
virtual currency. After you convert your money and pay the ransom, the cyber criminals may, or
may no, send the instruction to restore your files.
The best way to protect yourself from ransomware is to backup your imprtant files frequently.
If you are the victim of a ransomware attack, Take your computer to a qualified computer service
shop like the Best Buy Geek Squad where they should wipe your hard drive clean and reinstall the