Intrusion detection is necessary if you either suspect that someone has some form of illegitimate (and illegal) access to corporate sensitive data or would like to ensure that the information contained within your database is not stolen.
Although the first case is more serious than the second (prevention is always better than cure), a sound security infrastructure requires more than simply installing tried and tested policies and solutions. Intrusion detection, although paramount, is a passive form of security. Therefore, you need a set of tools that allow you to see whether people can penetrate these security measures.
Acunetix Web Vulnerability Scanner is one such tool. The web application layer is significantly different from the network layer simply because web applications (e.g., shopping carts, login forms, contact us forms) need to have direct access to your database.
Since your website needs to be public, all your security and intrusion detection mechanisms will allow public web traffic to communicate with your web application/s (generally over port 80/443). The web application has open access to the database in order to return (update) the requested (changed) information.
This means that at any point in time someone with significant knowledge of databases and coding can manipulate any single application on your website to yield (delete or change) data contained in the database.
The only way to ensure that this doesn’t happen is to scan your web applications regularly using a web vulnerability scanner such as Acunetix. The solution will tell you which web applications are weak and therefore can be manipulated. Acunetix WVS will report the type of weaknesses and give you recommendations how to best proceed in fixing these weaknesses that will be used by hackers to steal your data and sell it for profit. Moreover, if you have the burden of PCI compliance you are even liable to substantial fines.