Hello

This post opens set of articles devoted to computer security.

At first, I would like to give some basic definitions for variety of modern computer threats. All these threats are currently known as Malware.

Malware ("malicious software") is any application or file that is harmful to a computer or computer user. This would include, computer worms, viruses, Trojan horses, keyloggers, spyware, adware, web-page hijackers, driveby downloads, and any programming that gathers info about a computer user without their expressed permission.

5 years ago, the most security threats that most people came across were Viruses.

This is no longer the case!

There are new threats out; and they take no prisoners, no longer is an anti-virus application sufficient to stop the invaders, the web is a complex place and the technology is getting so advanced that you need to act now to protect your machine and your private\personal data.

A quick overview of some of the more common malware that you might find, sorted by level of threat:

SPYWARE

Spyware is any technology that aids in gathering information about a person or organisation without their knowledge. On the Internet (where it is sometimes called a spybot or tracking software), spyware is programming that is put in someone's computer to secretly gather information about the user and relay it to advertisers or other interested parties.

TROJAN

Trojans are malicious programs often used by hackers to attack target computers, usually to provide a backdoor into the system but sometimes just to cause destruction. Remote Access Trojans (RATs) are the most famous class of trojans and they usually come in two parts - a server that is sent to infect the victim, and a client that the hacker uses to connect to the server after the victim is infected. There are many ways that hackers can use to infect a target with a trojan, and careful security measures aren't always enough - a strong anti-trojan program can easily detect tens of thousands of trojans that would otherwise be near-impossible for a human to find.

VIRUS

A program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes. Viruses can also replicate themselves. All computer viruses are manmade. A simple virus that can duplicate itself over and over again is relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all available memory and crash the system. An even more dangerous type of virus is one capable of transmitting itself across networks and bypassing security systems.

WORMS

Worms are in a similar category to viruses. Usually spread by email and containing their own email engine, they attempt to spread themselves to all the people in your address books, impacting greatly on network traffic on the web. Sometimes you will find viruses also contain Worm code so the virus is able to mail multiple people using its email engine, whilst infecting the machine with a specific virus, making the sender of the virus hard to find as it looks like it has come from someone you know.

KEYLOGGERS

A keylogger is a program that has been dropped onto a PC that actively monitors all your keystrokes and mouse clicks to try to capture both personal data, passwords, and browser habits, it will also capture any data entered on any web site including secure sites like online bank sites. This data is then stored in an encrypted text file either on the machine or sent to a pre-defined server for the sender of the keylogger to access at his discretion.

ADWARE

Adware is any software application in which advertising banners are displayed while the program is running. The authors of these applications include additional code that delivers the ads, which can be viewed through pop-up windows or through a bar that appears on a computer screen. The justification for adware is that it helps recover programming development cost and helps to hold down the cost for the user.

HIJACKERS

A hijacker is a expression used to explain a registry entry on your machine that has been placed there to re-direct your browser to another site, usually ad-purposed. These are not normally harmful for the machine, other that the fact that it will stop you from getting to the web site you wish to visit. It is more of a frustration than a security risk; however, some Hijackers will attempt to redirect you from Hijack deleting sites.

Hope you like this article. Next time I will write about tools used to prevent of/remove particular threat types listed here.

Cheers,
Carl