VPNs: virtual private networks create a secure tunnel between two points, typically a corporate network central office and a remote branch office. The tunnel passes encrypted (scrambled) data over the public Internet, then decrypts it at the destination point. This protects data from hackers on its path over the Internet, and renders the data unreadable during its journey.

Denial of service: This is a hacker-based attack on a web server that prevents customers/visitors from gaining access to an organisation’s website. Usually launched by a worm virus (eg Code Red, Code Blue) that can replicate from computer to computer. There are also ‘distributed denial of service’ attacks, which simultaneously attack several servers at once.

Firewall: This is a system that provides both network access control and attack containment features to prevent and block unauthorised traffic entering the corporate network. A firewall checks each passing packet of data in respect of its starting point, destination, content, size etc.

Intrusion prevention: This detects network, application and hybrid attacks and provides alarms to network operators. It also has the ability to ‘drop’ the attack from the network to stop it from reaching its target.

Trojan Horse: This is an attack that is hidden within a seemingly legitimate attachment to an email received across the Internet. Once inside a PC it infects memory, processor and applications, then spreads to other network resources. In some cases it will establish contact with the hacker, enabling tunnels or embedded controls to infiltrate the corporate network.

Backdoor or U-turn attacks: These are methods of network attack aimed at small branch offices that have Internet access both locally and via the corporate VPN. Illegal entry is gained via the local link and, once behind the remote site’s VPN, the hacker can strike the corporate network via the VPN.

WLANs: Wireless local area networks are created using a broadcast medium. Wireless hackers are particularly dangerous as they can gain access to the network by broadcast proximity to the network (for example, in a car or on foot near the building where the WLAN is in operation).

Virus: A computer virus attacks by ‘piggy-backing’ on top of another program in order to be executed. Once it is running, it is then able to infect other programs or data files.

NetScreen Technologies Inc is a leading developer of integrated network security solutions that offer the security, performance and total cost of ownership required by enterprises and carriers. NetScreen’s innovative solutions provide key security technologies, such as virtual private networks, denial of service protection, and firewall and intrusion prevention, in a line of easy-to-manage security appliances and systems. NetScreen is publicly traded on the NASDAQ market under the symbol NSCN. For further information contact: Company Headquarters at 350 Oakmead Parkway, Sunnyvale, CA 94085, USA. Regional headquarters for Asia-Pacific and Europe are located in Hong Kong and Guildford, UK, respectively. More information on NetScreen’s products in Europe can be found at www.netscreen.com or by calling 08700 75 00 00.

Remote working Remote working can open up a company to new threats from hackers unless the right precautionary measures are put in place, writes Paul Drew from Tekdata. In today’s Internet-driven world the use of the teleworker is becoming more common. This is good for both workers and businesses as it reduces overheads and travelling time, increases productivity through flexible working and also allows companies to recruit the quality of staff they need even though they may not live near the companies’ offices. Over 80 per cent of companies now have staff who work from home on a regular or occasional basis, according to the latest research. A survey carried out by SonicWALL Inc shows that 83 per cent of companies now allow teleworking, with 43 per cent having staff who access the company’s network from home, usually via the Internet. Big businesses are more likely to encourage the practice than their smaller cousins. Home working is now prevalent in 98 per cent of large companies (with £20 million or more turnover) compared with 91 per cent of small-to-medium sized enterprises (with £5–20 million turnover) and 79 per cent of small businesses (with £1–5 million turnover).

Once the main method of connecting the remote worker to the corporate system was through point-to-point dial-up connections; but now, with technological advances and increasing Internet-driven business activities, remote workers can easily connect from anywhere in the world. Using VPNs (Virtual Private Networks) teleworkers are connecting to corporate networks and accessing day-to-day business-critical systems and information. This process has led to many domestic networks being created within remote workers’ homes, and increasingly these networks or laptops are being used by the whole family. Activities such as file swapping, instant messaging, online gaming and video conferencing can inadvertently open up back-door holes for hackers to hijack corporate VPNs. Directors, under new data protection laws, are now legally responsible for information held on corporate networks concerning their employees and customers. Various systems can create a ‘trusted zone’ of network security between the corporate office and the telecommuter, protecting your corporate network against malicious intrusions that occur when work computers share broadband Internet access with multiple-networked family computers. This trusted zone ensures that harmful intrusion cannot traverse the home network to the corporate network, and that in-home users cannot access the corporate network.