by Kyle Bailey

Has computer security been on your mind lately? It should be, especially if you have access to the Internet—and I’m not just talking about owning a Web server or using E-mail. I’m also talking about those of you who use dial-up and direct-connect methods such as cable or DSL. Those of you who own a copy of PC Anywhere, or some other machine-sharing technology, are also at risk.

The best part of computer technology is also the basis of the problem: the sharing of your data, and the access that must be granted for it.

Computer-related security is a problem for individuals, large companies, small businesses. It has been made a spotlight issue by recent denial of service (DoS) attacks on enormous and popular sites such as CNN, eBay, Buy.Com, Amazon and Zdnet. E-mail-borne viruses have also been prevalent, with the flurry of ‘I Love You’ and ‘Love Bug’ messages being self-replicated on the Internet by organizations and individuals that have not taken the steps to ensure they’re protected.

In computer security, there are no 100% guarantees. It’s the same as vehicle or home security systems—you try to deter all but the most dedicated intruders. But if a hacker really wants to access your data, he will find a way to breach any security system.

As with most security situations, your weakest link is always the human element. The largest security risk for any company are employees who leave their log-ins exposed, or use their own names for passwords. Hackers routinely use unsuspecting staff members to provide them with log-ins and passwords. A hacker will call a staff member, posing as a member of the IT team, and ask him to confirm his user ID for auditing purposes. Hackers are also known to partake in ‘dumpster diving’, literally wading through garbage in search of information that will gain them unfettered access to your secrets.

Most computer security issues are less obvious—until disaster strikes. Digital attacks come in a variety of forms and under many names, the most common being ‘virus’. Viruses are programs that insert themselves into files and then replicate at will, infecting your system and any systems connected to yours. Their effect can be as innocuous as adding a permanent smiley face to your system, to causing a catastrophe that turns all of your hard drive files into digital vegetables. Some wait for specific dates to wreak havoc, with Friday the 13th a popular destruction day.

Other invasive programs spread by users sharing files are Trojan Horses, or Trojans. Unlike the condoms, these do not protect you. These malicious little programs initially appear to do something useful or entertaining, like running an interesting screensaver. In the process, they do other things that destroy files, or create ‘back doors’ which allow intruders to gain access to your network. Trojans can also search your system for specific data types, then transmit that information back to their masters. And you’d never know, because they can delete themselves after their mission is accomplished. Imagine having your business plan or customer database being quietly picked up and sent to your competitors.

A computer Worm is a self-replicating program that does not alter files but resides in your computer’s active memory and duplicates itself via your computer network. Worms use your systems’ automatic and invisible communication functions, and are usually only noticed when your computer network grinds slowly to a halt as its resources are used up. Some of the newer Worms also pack a wicked payload that can destroy files.

Beyond these variants of malicious programs are any number of security issues that come into play once you have a direct Internet connection or a dedicated Web server, FTP server or other public/private access point on the information superhighway.

The best solution for protection is to ensure that you have a firewall installed on your various network connections. A firewall is a dedicated piece of hardware or software designed to be the first line of defence against unauthorized users trying to gain access to your private network. It is a gatekeeper, and all data travelling in or out is screened against a set of user-defined filters that set specific security criteria for all network traffic.

The methods that these firewalls employ fall into four groups of techniques:

Packet Filtering: The firewall examines each packet of data that enters or leaves your server and accepts or rejects it based on your rules. Packet filtering is effective and transparent to your server’s users. Setting the filtering rules can be difficult on complex servers, but many software vendors are streamlining the process. Packet Filtering is vulnerable to DoS attacks.

Application Gateways: This technique is used for specific applications, such as file transfer and telnet access. It also is valuable, but can result in performance loss for your users.

Circuit-Level Gateway: This is also used for specific transfer protocol applications, such as TCP or UDP. Once a network connection has been granted, data packets can flow between the hosts without further checking.

Proxy Server: This process intercepts all data entering and leaving your network. The Proxy Server masks your network’s true address, thus stopping prying eyes from finding the true destination.

Most firewalls employ more than one of these methods at any given time. Additional network security can be added by having your data encrypted, with only authorized users having the decryption key. While this is very effective for securing transmitted data, it does hinder performance.

There are hundreds of software and hardware vendors that provide the necessary tools to help you protect yourself from the various forms of attack. The most popular and complete virus scanning and elimination software is from Norton or McAfee. There is no simple solution for firewall software, as it varies between server configurations and operating systems—not to mention user requirements and budgets.

Here are some tips to help you avoid becoming the victim of a digital mugger:

Get a good anti-virus program and use it continuously.

Update the virus signatures at least weekly, preferably daily.

Be wary of all attachments.

Scan your system thoroughly at least monthly, preferably weekly.

Regularly make multiple back-ups of your entire hard drive.

Ensure that your browser, e-mail, client and critical system files are up-dated regularly. Most vendors offer security patch up-dates as vulnerabilities are identified.

Get a firewall installed and monitor all network traffic

These efforts won’t guarantee that you won’t be a victim, but you definitely lessen your chances by being prepared.

Kyle Bailey is the Big Cheeze at E-Cubed Media Synthesis, an eBusiness strategy firm. He can be reached at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it This e-mail address is being protected from spam bots, you need JavaScript enabled to view it or (604) 878-0765.