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Spies: Spies are out to get secret information. It may be difficult to detect break-ins by spies since they will probably leave no trace if they get what they are looking for.
A personal firewall, therefore, is one of
methods you can use to deny such intrusions.
How Firewalls work? Firewalls basically work as a filter between your application and network connection. They act as gatekeepers and as per your settings, show a port as open or closed for communication. You can grant rights for different applications to gain access to
internet and also in a reverse manner by blocking outside applications trying to use ports and protocols and preventing attacks. Hence you can block ports that you don’t use or even block common ports used by Trojans.
Using Firewalls you can also block protocols, so restricting access to NetBIOS will prevent computers on
network from accessing your data. Firewalls often use a combination of ports, protocols, and application level security to give you
desired security.
Firewalls are configured to discard packets with particular attributes such as:
Specific source or destination IP addresses. Specific protocol types TCP flags set/clear in
packet header.
Choosing a firewall: Choose
firewalls which have
ability to ward of all intrusion attempts, control applications that can access
internet, preventing
malicious scripts or controls from stealing information or uploading files and prevent Trojans and other backdoor agents from running as servers.
The purpose of having a firewall cannot be diminished in order to gain speed. However, secure, high-performance firewalls are required to remove
bottleneck when using high speed Internet connections. The World-Wide-Web makes possible
generation of enormous amounts of traffic at
click of a mouse.
Some of
good firewall performers available in
market are below:
•BlackICE Defender •eSafe Desktop •McAfee Personal Firewall •Neowatch •Norton Personal Firewall •PGP Desktop Security •Sygate Personal Firewalls •Tiny Personal Firewall •Zone Alarm •Zone Alarm Pro
Most of these firewalls are free for personal use or offer a free trial period. All
personal firewalls available can’t ensure 100% security for your machine. Regular maintenance of
machine is needed for ensuring safety.
Some of
tasks advised for maintaining system not prone to intrusions:
•Disable file and print sharing if you are not going to be on network. •Update your antivirus signature files regularly. •Use a specialized Trojan cleaner. •Regular apply security patches to your software and operating system. •Don’t open email attachments if you have don’t know
contents it may contain. •Don’t allow unknown applications to access to
internet or to your system. •Regularly check log files of your personal firewall and antivirus software. •Disable ActiveX and java and uninstall windows scripting host if not required. •Turn off Macros in Applications like Microsoft Office and turn macro protection on. •Check
open ports of your system and see them against
common list of Trojans ports to see if they are being used by some Trojan. •Log Off from your internet connection if not required. Being online on
internet for long duration gives any intruder more and sufficient time to breach system security. •Unplug peripherals like web cam, microphone if they are not being used.

Pawan Bangar, Technical Director , Birbals, India