There are an estimated 58,000 computer viruses in existence worldwide, and they are multiplying at a disturbing rate, with 400 to 500 new viruses emerging each month. Over the past year, there has been a 65 percent increase in security threats to information systems. In the past two years, the number of internal network intrusions has almost quadrupled. Despite these astonishing statistics, the Fifth Annual Information Security Survey by Ernst & Young found that only 64 percent of respondents monitor networks for security incidents and an equal number have no response plan for security breaches.

The reality is that any small business with a broadband connection to the Internet risks becoming a victim of a cyber crime. Skilled computer hackers are intent on breaking into private computer networks. These attackers can infect systems with viruses or gain access to sensitive files that could include financial information and confidential customer records. Many hackers can penetrate networks and use them as a launch pad for sending junk e-mails to disrupt or overload other networks. Ultimately, such attacks can crash a network, potentially causing data to be permanently deleted or irreparably damaging computer equipment or systems.

Cyber-crime also packs a mean punch in terms of dollars lost. For example, the cost of a denial-of-service (DoS) attack, in which hackers attack a site with phony traffic in order to overwhelm and crash servers, can run into the millions of dollars. In February 2000, in a well-coordinated DoS attack, hackers successfully crippled Amazon.com, eBay, CNN, and Buy.com, one day after a similar attack halted Yahoo's service for hours. Since then, numerous small businesses have been the victim of DoS attacks.

However, the news is not all bad. While the threat of hackers and viruses remains real, there are a number of simple, highly effective steps that small-business owners and network administrators can take to protect their systems against cyber-sabotage (not to mention sleep better at night). Following are some key pointers.

Implement a firewall

As the name implies, a firewall is a barrier that keeps destructive forces away from computer networks. All firewalls, whether software systems or hardware computer appliances, intercept network traffic, allowing only authorized data to pass through. A firewall is your system's best defense against would-be intruders.

The cost of implementing a firewall depends on product features and implementation. The price can range from a few hundred to thousands of dollars.

To be effective, firewalls must work in concert with other efforts to provide a safe computing environment. Cyber security is a process, not a product, and firewalls should be viewed as one component of the strategy in achieving network security.

Develop a corporate security policy

Establish a corporate security policy that details company practices to secure the network. The policy should direct employees to choose unique passwords. This is important because brute-force password cracking programs readily available on the Web contain tens of thousands of common passwords, such as 1234, abcd, admin, access, and buzz. Accordingly, companies should require passwords to be non-dictionary terms and a combination of letters and numbers. Passwords should also be changed every 90 days so that by the time a hacker or co-worker has gained access to a password, it's already changed.

When an individual is no longer employed by the company, immediately eliminate his or her access to the network by deleting the username and password.

The corporate policy should outline consequences for current and former employees found tampering with or entering the network without authorization.

Install antivirus software

Antivirus software is a powerful tool against network invasions. All computers should run the most recent version of the virus protection subscription. Ideally, a server should be configured to push virus updates out periodically to all client systems, since new virus signatures are discovered nearly every day. Viruses are among the greatest threats to network firewalls and can spread quickly. Employees should be educated about viruses and discouraged from opening unexpected e-mail attachments, or e-mail from unknown senders.

Two common antivirus software packages are Norton and McAfee; the price will vary depending on how many agents are needed for the network, and what additional packages are required, such as Antivirus for Exchange Server or SQL Server.

Keep operating systems up to date

Upgrade operating systems frequently and be sure to regularly install the latest patches or versions of software. Updates and patches are often free over the Web. Maintaining the most recent version of a software product will help you stay ahead of hackers. On older versions of software, hackers have had time to break the code, which allows them to easily disrupt systems. This means that a computer running version 5.0 of a product is typically more secure than a system running version 4.0. Check Windows >www.windowsupdate.com< periodically for the latest patches.

Don't run unnecessary network services

When installing systems, servers in particular, every network service is a potential security hole. For this reason, any non-essential features should be disabled. For example, a domain controller or file server typically doesn't need to run the IIS Web/FTP servers, so these options should not even be installed. There have been numerous viruses and exploits for IIS, and if an organization has it installed but is not actively using the feature, it is less likely to be updated regularly, often presenting an even larger security threat than it would to someone who actively uses the feature.

In addition, allow only the software your employees need to do their job effectively. If employees don't need instant messaging or file-sharing applications, don't allow them to be installed, and block their access at the firewall. By limiting the network and excluding nonessential services, security risks can be greatly reduced.

Conduct a vulnerability test

Conducting a vulnerability test is a cost-effective way to evaluate the current security program. This test highlights flaws and limitations in the program, and as a result, experts can offer ways to decrease exposure to a potential hacker. The best method for conducting a vulnerability test is to contact a computer consulting company and provide access to your system for a day or two. This will provide ample time for network appraisal and follow-up discussion and planning.

Read current literature about network security. Numerous books, magazines, and online resources offer current insights on effective prevention tools, and "lessons learned" from recent attacks. Also, the Web provides ample and very current information about security--type in the keywords network security on any search engine site.

These types of assurances can offer both peace of mind and real security to business owners. Preventive security measures, combined with a little bit of common sense and network vulnerabilities awareness, can ensure that your business won't be a hacker's next victim.