A compromised computer in turn can be harnessed as a tool to launch attacks on computers and servers on the Internet.

Internet security has become a top priority issue for both corporate and government computers. The increased use of portable computers, e-mail, remote link-ups to servers, and growing links within networks and between networks means that any computer that has a virus is increasingly likely to communicate with and infect other computers and servers than would have been true a few years ago.

Our customers are concerned when viruses and Spyware infect their computers. It conjures up terrifying images of the bubonic plague that ravaged Europe during the past century or epidemics now decimating Africa. One company had to reinstall Microsoft Windows after Spyware disabled its computers. It also had to reinstall all of its application software.

According to statistics from the accounting firm PricewaterhouseCoopers, viruses and other destructive actions taken by computer hackers will cost businesses an estimated $1.6 trillion by the end of this year alone. There are no figures for losses suffered by people from our industry. Contractors and wholesalers need to be more aware of how the Internet could affect their security and privacy. The Internet can transform an isolated computer into a vibrant node for exchanging information on the global network known as the Internet.

Hackers Prowling The Internet: Denial Of Service

With a dial-up connection, your IP address is different each time you connect to the Internet. Such connections tend to be slow and are limited by the speeds of the dial-up modem and the phone line. It is extremely difficult to hack a computer connected to a dial-up modem because it is difficult to track and identify such a moving target.

With a Digital Subscriber Line (DSL) or cable connection, the IP address does not change between sessions. DSL is the fastest way to access the Internet because the system is always on and can move data at fiber optic speeds. It's great for downloading music and videos, but an open invitation to hackers. A corporate or personal firewall might help, but a determined hacker can penetrate even these. Expert hackers exchange sophisticated software tools to exploit human and technical weaknesses in the security of computer systems. They use password crackers, war dialers, vulnerability scanners, sniffers, IP spoofers and others. Many of these tools are readily available on the Internet. One such attack shut down the Yahoo site for several hours in February 2000. A Distributed Denial of Service (DDOS) attack in August 2003 crippled the Microsoft Corp.'s Web site for two hours.

According to Gibson Research, a computer security firm, “Nothing more than the whim of a 13-year old hacker is required to knock any user, site, or server right off the Internet.” The gruesome details of a DDOS attack by a total of 447 Windows PCs on their network are described at: http://www.grc.com/dos/grcdos.htm.

A compromised computer or network can be used to launch a DDOS attack on the Internet. It's hard to believe, but due to shortcomings in previous Microsoft Operating Systems (Windows 3.x/95/98/ME or NT), it was impossible for an application to “spoof” its source IP or generate malicious data packets that could bring down a network by exceeding its bandwidth capacity. It took major improvements like Windows 2000 and Windows XP to make it easier for hackers to successfully launch DDOS attacks on computer networks. According to Gibson Research, @Home and Road Runner provided cable-based Internet access to host machines most often attacked by malicious hackers.

Minefields On The Internet Battleground: Viruses, Spyware And Trojans

A logic bomb is software concealed in the main computer and set to activate at some point in the future, destroying data.

A Trojan Horse masquerades as legitimate software and when triggered, delivers a payload that may destroy files or disks. It can allow a remote user to access and control your computer without your knowledge whenever you are on the Internet.

A computer worm spreads like a virus but is an independent software application. The Nimda worm only infects Microsoft Windows IIS servers. Check on the types of servers used on any Web site by pointing your browser to this link:

http://uptime.netcraft.com/up/graph/?host=

Spyware is software that a server placed on your computer after you granted your consent to the terms and conditions on its Web site. This may be quickly followed by a confirmation e-mail. You may also receive e-mail offers from the hundreds of companies that purchased your e-mail address from the site you just visited. The e-mail may contain attachments with Spyware that write data to an obscure area of your computer known as the Windows Registry. Spyware takes up additional Internet bandwidth and slows down your activity on the Internet. Hijackers are a type of SpyWare that herd browsers toward particular Web sites. Conflicts between Spyware programs could cripple your browser. This problem is so serious that the U.S. Congress is currently enacting legislation to control or eliminate Spyware. You may protect yourself from Spyware by downloading and installing SpywareGuard. Point your browser to this link: http://www.spychecker.com/download/ download_spywareguard.html

Spyware gathers data on your Internet activity and continually transmits information to the parent site. Ad-aware is a software package for detecting and removing SpyWare and Hijackers. SpywareGuard is a free software package that alerts users each time an attempt is made to change the Windows Registry.

Internet Browsers And Computer Security: Replacing Internet Explorer

Internet Explorer, sometimes called Internet Exploder, is the worst way to browse the Internet. Unfortunately, most businesses use it simply because it comes bundled with their computers. Being the preferred browser on 97% of the world's computers also implies that the much publicized security flaws in the browser will affect the majority of the world's computers. Microsoft has attempted to rescue its IE 6.0 (78-MB) behemoth with monthly security patches distributed over the Internet. The December 2003 patch was not issued because yet another security flaw was discovered just before the release date. The latest flaw works by “spoofing” a legitimate domain name in the address bar using a specially crafted Web site address. A hacker could exploit this flaw to obtain site passwords, credit card numbers and other personally identifiable information, including Social Security numbers. The list of Internet Explorer security flaws is growing by the hour and this might be the time to “explore” more secure Internet browsers.

-- The Opera browser (15-MB) can be downloaded by pointing your browser to this link: http://www.opera.com/

-- Point your browser to this link to download the Mozilla open source browser (12-MB): http://www.mozilla.org/

-- Point your browser to this link to download the K-Meleon browser

(5-MB): http://kmeleon.sourceforge.net/download.php

These Internet browsers may be safer merely because they have been ignored by hackers as they only affect 3% of the world's computers.

Countermeasures: Surviving And Thriving On The Internet

Faster may not be necessarily better for Internet security. DSL connections can speed up your surfing experience on the Internet but they are also a good target for hackers. Use state-of-the-art firewall and intrusion detection technology to keep abreast of wily hackers.

Internet Explorer is highly insecure because it's the most widely hacked Internet browser on the market. Switching to Mozilla or another browser with few or no security holes could significantly improve your Internet security. Using the technique outlined above one can identify and avoid Web sites that are hosted on insecure servers like the Windows IIS.

Improvements to Microsoft Windows have made it worse for Internet security. The Linux operating system, while still in its infancy, holds promise if it can maintain its current level of security.

Many of the intrusions on your computer system are made possible by unsolicited e-mail. You might consider using integrated security appliances such as Symantec Corp.'s Gateway Security 5400 series or Internet Security Systems Proventia. These devices provide content filtering, intrusion detection, virtual private networking and intelligent application-aware firewalls.

Summary And Conclusion

It is important to realize that Internet security is an ongoing process. It requires a multitude of approaches that vary with the nature of the underlying threat. Ignoring security could cost you a lot in hours of work lost in restoring your computer to its original state.