Let’s shift back to a security discussion and take a look at threats. Any intelligent discussion of threats starts out by looking at what you are protecting, how it can be threatened, and the impact if one of the threats actually occurs. Let’s take a look at some threats:
Defacing a Web Site
In the past this has been one of the most common and visible “hacker” threats. If you have a simple “brochure ware” site, the most reasonable approach may be to simply have a good backup you can restore. If, for example, you have a DreamWeaver site, you might simply mutter something appropriate under your breath and hit the button to republish the site.
On the other hand, if you have an ecommerce site that your company depends on… This site is obviously important and must be protected.
This is an example of considering exposure, impact and cost. You shouldn’t spend too much to protect the “brochure ware” site. You shouldn’t spend too little to protect the ecommerce site. You should do the analysis of what is appropriate!
Using a System for Other Purposes
Having your system hijacked and turned into a zombie spewing malware and spam is a bad thing. In addition to the direct impact on the system, this is likely to get your whole domain blacklisted and effectively kicked off the internet. Consider both the direct and indirect impact of someone taking over your system – this is worth defending against.
Data theft can be catastrophic. The cost can go far beyond the direct costs – just ask Target about their credit card breach!
From the computer side, protecting data requires solid access controls, encryption, and operational controls. But you should ask some other questions: Why do you have that data at all? Do you need to store the data? Which computers actually need access to that data? In a uprising number of cases you may not actually need that data at all! As a simple example, don’t store passwords – store password hashes! Properly salted, of course…
This can be very serious. In many cases the absolute worst thing that can happen is for data to be changed. This can mean that none of the data can be trusted. Depending on the data and the change, this can range from a nuisance to life threatening. We will dig into this topic in more detail in the future.
Data destruction can be malicious or accidental. What will you do if a disk drive crashes? What will you do if someone – maybe even you – “accidently” deletes a critical file? How about an evil hacker breaking in and deleting data?
Even worse, what if the evil hacker deletes every tenth record in your database? Or if there is data corruption in part of a file or database?
Data destruction can be subtle. You need to worry about preventing it, detecting it, and recovering from it.
Changing software is a severe and subtle risk! The bottom line is to make sure you can detect it if it occurs – yes, this is even more important than preventing it. A good example of what can happen is a recent Computerworld Sharktank article. In this cases, the people making changes to the system were authorized to do this – but the impact of those changes should have been detected.
Degraded System Availability or Performance
If a computer is performing an important business function, availability and performance have direct and measurable cost. You need to continuously measure the availability and performance of critical application services.