Firewall Your Network
A firewall is a security device or program that separates two or more networks. Firewalls prevent unauthorised access to an internal network (your network) from an external network (the internet), but also allows internal users access external resources.
When connected to the Internet your systems are vulnerable to attack – malicious or otherwise – from hackers and intruders. How they gain access can vary.
Attacks you should protect your systems from:
Social engineering – A hacker pretends to be an authorised user. This is done by gaining physical access to equipment through social means and/or tricking authorised users into giving out a password or revealing potential holes in the networks security.
Eavesdropping – By listening to a network connection, hackers and intruders can steal passwords, files and messages which can then be used to access the network.
War dialling – Hackers dial telephone numbers at random, hoping to find a modem that will answer their calls and provide a direct path into the network.
Attacking the host – If a server or host is incorrectly set up or administered, operating systems may be vulnerable to unauthorised access.
Password guessing – Administrators can prevent this by setting and enforcing requirements for difficult-to-guess alphanumeric passwords.
Denial-of-service (Dos) attacks – When a TCP connection is started, the hacker sets the SYN flag in the TCP header. Then the hacker makes the IP address unreachable so the server cannot complete the connection. But it still reserves the system resources for the address. If the connection requests build up, the server is spending all its time servicing the hacker that it cannot service legitimate clients, denies them the service.
Protocol-based attacks – Hackers search for UDP or TCP ports using port-scanning software. Once an active port is found, it can be used to exploit known weaknesses in protocols and, in turn, gain access to your network.
Contact us for a security check!