The new and updated version of the PCI Data Security Standard is as much about refining and improving the protection afforded by the DSS as re-launching the standard and attempting to galvanise renewed focus onto PCI compliance.
Many organisations have still chosen to delay the implementation of their PCI program, being wary of the resource requirements necessary to manage PCI compliance.
The new version of the PCI DSS makes it harder to continue to delay adoption and this will undoubtedly be the time that many organisations decide to face the music.
This whitepaper provides practical advice on how taking a ‘baby steps’ approach to PCI compliance, leveraging automated monitoring technology for file integrity and event logs, will only require a few minutes each day.
PCI Compliance Is Hard for Everyone
In some respects, it can be argued that, the less IT ‘stuff’ an organisation has, the fewer resources are going to be needed to run it. However, with PCI compliance there are still always 12 Requirements and 650 sub-requirements in the PCI DSS to cover, regardless of whether you are a trillion dollar multinational or an SME company.
Spending some time recently with one of our smaller-scale resourced customers we were discussing – what else – PCI compliance for their IT Systems. The customer in question is a West-Coast USA based Metropolitan Theatre Operator and, being a theatre, their core business activity is bringing artistic productions to the people. IT is very much a necessary evil and as such in this instance there is essentially a four man team tasked with delivering IT.
What does ‘Secure’ look like?
The principles of good security remain the same for both ends of the organisation-size scale – you can only identify security threats if you know what business-as-usual, regular running looks like.
Establishing this baseline understanding will take time – 8 to 24 weeks in fact, because you are going to need a sufficiently wide perspective of what ‘regular’ looks like – and so we strongly advocate a baby-steps approach to PCI for all organisations, but especially those with smaller IT teams.
We argue strongly that doing the basics well first, then expanding the scope of security measures is much more likely to succeed and be effective than trying to do everything at once and in a hurry. Even if this means PCI Compliance will take months to implement, this is a better strategy than implementing an unsupportable and too-broad a range of measures. In other words, it’s better to work at a pace that you can cope with, than to go too fast and go into overload.
This is the five-step program we recommended to our theatre group client, although it actually has merit for any size of organisation.
1. Classify Your ‘In Scope of PCI’ Estate
You first need to understand where cardholder data resides. When we talk about cardholder data ‘residing’ this is deliberately different to the more usual term of cardholder data ‘storage’. Card data passing through a PC, even it is encrypted and immediately transferred elsewhere for processing or storage, has still been ‘stored’ on that PC. You also need to include devices that share the same network as card data storing devices.
(Note: The latest version of the PCI DSS goes further than ever, posing some tricky questions about how your applications ensure the safeguard of CHD ‘in memory’. The intent is that security becomes a higher priority design and testing consideration when developing card data handling applications, promoting awareness of the need to mitigate buffer overflow, SQL injection and cross-site scripting vulnerabilities)
Now classify your device groups. For the example of our Theatre client, they have six core servers that process bookings. They also have around 25 PCs being used for Box Office functions. There are then around 125 other PCs being used for Admin and general business tasks.
So we would define ‘PCI Server’, ‘Box Office PC’ and ‘General PC’ classes. Firewall devices are also a key class, but other network devices can be grouped together and left to a later phase, simply because switches and routers are relatively less significant from a security standpoint.
Remember – this isn’t cutting corners or sweeping dirt under the carpet, but a pragmatic approach to doing the most important basics well first, or in other words, taking the long view on PCI Compliance.
2. Make a big assumption on what to classify as PCI devices
We now apply an assumption to these Device Groups – that is, that devices within each class are so similar in terms of their make-up and behaviour, that monitoring one or two sample devices from any class will provide an accurate representation of all other devices in the same class.
We all know what can happen when you assume anything but this assumption is a good one. This is all about taking baby steps to compliance and, having declared up front that we are adopting a strategy that is practical for our organisation and our available resources, this provides an effective strategy.
The idea is that we get a good idea of what normal operation looks like, but in a controlled and manageable manner. We won’t get flooded with file integrity changes or overwhelmed with event log data, but we will see a representative range of behaviour patterns to understand what we are going to be dealing with. Before we can even hope to identify potential security events, we need to know what our starting point is or, in other words, our steady-state/baseline of regular events.
Given the device groups already outlined, we recommend targeting one or two servers – say a web server and a general application server – one or two Box Office PCs and one or two general PCs.
3. Watch and analyse logs and server behaviours
You’ll begin to see file changes and events being generated by your monitored devices and about ten minutes later you’ll be wondering what they all are. Some will be self-explanatory, some not so. Warning, at this stage, be prepared for an influx of new fixes and adjustments to existing systems. Misconfigurations will suddenly be brought into focus by monitoring, for example, service accounts for which the password expired months ago will suddenly be visible by their repeated failures to authenticate. These will need to be removed or repaired - how will you be able to identify a Worm running a dictionary attack if your network is already home to legitimate, but similarly operating, service accounts?
Either way, the imperative of tight Change Control will become very apparent.
If changes are being made at random, how can you begin to associate change alerts from your File Integrity Monitoring (FIM) system with intended ‘good’ changes and consequently, to detect genuinely unexpected changes which could be malicious?
Much easier if you can know in advance when changes are likely to happen – say, schedule the third Thursday in any month for patching. If you then see changes detected on a Monday these are exceptional by default. OK, there will always be a need for emergency fixes and changes but getting in control of the notification and documentation of Changes really starts to make sense when you begin to get serious about security.
Similarly from a log analysis standpoint – once you begin capturing logs in line with PCI DSS Requirement 10 you quickly see a load of activity that you never knew was happening before. Is it normal, should you be worried by events that don’t immediately make sense? There is no alternative but to get intimate with your logs and begin understanding what regular activity looks like – otherwise you will never be able to detect the irregular and potentially harmful.
4. Tune in your log analysis rule set
You’ll now have a manageable volume of file integrity alerts and event log messages to help you improve your internal processes, mainly with respect to change management, and to ‘tune in’ your log analysis rule set so that it has the intelligence to process events automatically and only alert you to the unexpected, for example, either a known set of events but with an unusual frequency, or previously unseen events.
At this point, Summary Reports collating file changes on a per server basis are essential as a means of easily verifying that the Change Management discipline is being observed. This is the time to hold your nerve and see this learning phase through to a conclusion where you and your monitoring systems are in control – you see what you expect to see on a daily basis, you get changes when they are planned to happen.
In line with the new PCI DSS V3.0, much greater emphasis is being placed on system hardening and vulnerability management, on the basis that prevention is always better than cure. The requirement for more comprehensive Pen Testing underwrites this. But this is the point at which a rigorously applied Hardened Build Standard should be established and applied to all devices. While it is good to have mature, sensitive monitoring systems in place to detect security incidents, it is much better to bolster system defences and avoid InfoSec problems in the first place.
5. Implement your PCI DSS V3.0 File Integrity Monitoring
Now you are in control of what ‘regular operation’ looks like, you can begin expanding the scope of your File Integrity and Logging measures to cover all devices.
Logically, although there will be a much higher volume of events being gathered from systems, these will be within the bounds of ‘known, expected’ events. Similarly, now that your Change Management processes have been matured, file integrity changes and other configuration changes will only be detected during scheduled, planned maintenance periods. Ideally your FIM system will be integrated with your Change Management process so that events can be categorised as Planned Changes and reconciled with RFC (Request for Change) details. In other words, close the loop and repeat.
There are no real shortcuts to PCI Compliance and you will routinely read and hear the PCI Security Standards Council reinforce the messages that there are ‘no Silver Bullets for PCI Compliance’ and how a ‘Check box’ approach to compliance will not make your organisation secure. PCI DSS V3.0 reinforces this message, that a continuous approach to compliance and security is what is expected, not a ‘stop-start’ approach, doing just enough to satisfy a QSA once a year. Doing nothing is absolutely not an option any more.
New Net Technologies is a leading provider of PCI DSS and general Security & Compliance solutions. As both a Software Manufacturer and Security Services Provider, we are firmly focused on helping organisations protect their sensitive data in an efficient and cost effective manner.
For more information on NNT go to http://www.newnettechnologies.com/file-integrity-monitoring.html