- A guide to securing your home computer system with a Linux firewall
- Is your home system at risk?
- What's safe?
- Is your home system a server?
- Are broadband connections more vulnerable?
- What ports are open?
- Using netstat to list ports
- Is Windows file sharing a risk?
- Using a port scan to test your system
- Checking for Windows NetBIOS risks
If you're getting a cable modem or some other broadband connection, you've probably had someone tell you that it will make your system vulnerable to an attacker. While this isn't exactly true (any system connected to the Internet is vulnerable, not just those with broadband connections), three things make servers with broadband connections more vulnerable than servers on dialup connections:
A 24-7 connection
Static IP address
A broadband connection is always on. This means that someone trying to crack into your system potentially has access to your computer any time of day.
Broadband connections mean faster downloads for youand for anyone who has hacked into your system. Dialup connections are slow enough to generally discourage any cracker from trying to download your Quicken files with all of your financial information. The high speed of broadband means that all of the important files on your hard drive can be downloaded by a cracker in just minutes.
On a dialup connection, your IP address is different every time you connect. On a broadband connection, your IP address doesn't change for a long time, if at all. If someone has found a way into your system and the IP address hasn't changed, they can easily reconnect. One trick of crackers is to scan a system for vulnerabilities and then come back later at a time when you unlikely to be on the computer to do their dirty work.