Having a tightly controlled firewall on the perimeter of a network will prevent incoming malicious connections and is a vital component within the security function. However, sophisticated and devious methods, designed to trick users into allowing malware (malicious software) onto their computers remain prevalent, making antivirus software at client / server level as important as ever.

Viral attacks can take many forms. As manufacturers of operating systems develop the effectiveness of their security patching, creators of malware adopt more inventive methods to infiltrate networks and PCs.

Virus: a piece of software which attaches itself to bona-fide programs. A virus may, for example, attach itself to a spreadsheet program, then each time the program runs, the virus runs too with the opportunity to reproduce itself by attaching to other programs or cause mayhem.

Email Virus: a virus that spreads as an attachment to an email message and usually replicates itself by automatically mailing itself to the contacts in the victims email address book. Some email viruses can be launched by merely viewing the infected message in the preview pane of the email software.

Trojan Horse: a computer program which claims to serve a particular purpose, a game for example, but instead is designed to carry out a specific harmful function once installed.

Worm: a piece of software that uses computer networks and security holes to replicate itself. Unlike a virus, a worm does not need to attach itself to a program. The worm sends copies of itself to other computers on the network using the security holes it has detected and begins replicating from those devices.

Spyware: a piece of malware that can be installed on a computer to collect information about the user without their knowledge. The presence of spyware can be difficult to detect. The term spyware suggests software that secretly monitors computer use; however the functions of spyware can extend to such things as installing additional software and redirecting Web browser activity. Spyware is also known to change computer settings, resulting in slow connection speeds, different home pages and / or loss of Internet connection or functionality of other programs.

IP Blacklisting
Spam is unsolicited commercial email. The most common types of spam include prescription drugs and remedies, get-rich-quick schemes, financial services and bargain price or pirated software. Spam email accounts for more than half the email sent worldwide. People send spam because it is profitable. Spammers can send countless emails in one campaign for a negligible cost and if they can hijack other computers to send the mail the cost is further reduced. If just one recipient in thousands makes a purchase, the spammer can make a profit.

Spam is not only a time wasting annoyance, but can be offensive to the recipient. Victims of hijacking unwittingly bombard other users with spam. Spammers are careful to ensure they cannot be traced, so it is the company with the hijacked computer who receives the complaints and whose reputation may be harmed.

Anti-spam programs can detect unwanted email and prevent it from reaching users’ inboxes, using a combination of methods to decide whether an email is likely to be spam. Probably the most common method is to block email that comes from addresses on a blacklist. This can be a commercially available list or a local list of addresses that have previously sent spam to your company.

Being blacklisted impedes your emailcommunication with customers and suppliers, slowing business and risking missed opportunities.

Find out if your IP address is blacklisted