Let’s wrap up our use case discussions for Continuous Security Monitoring by digging into how CSM can contribute to your compliance efforts. We know the way we staged these use cases (first attack, then change control) is bass-ackwards from how most folks implement monitoring. Compliance is typically the first use cases implemented, mostly because PCI-DSS mandates it. Regardless of how you adopt the technology, what you want to do is make sure whatever monitoring infrastructure you put in place will be extensible and relevant to all your use cases.

We described the compliance use case as:

Compliance is the check-the-box use case, where a mandate or guidance requires monitoring and/or scanning technology; less sophisticated organizations have no choice but to do something. But keep in mind the mandated product of this initiative is documentation that you are doing something – not necessarily an improved security posture, identification of security issues, or confirmation of activity.

Dissecting the language above, you see that the goal of compliance is to document and substantiate the controls you have in place to pacify an auditor. It is not to solve actual security problems. Yes, that is a nuance, and if you adequately protect information assets you are likely be able to prove compliance. But the converse is clearly not true. Just being compliant does not mean you are secure.

In terms of frequency of monitoring, you have a lot more leeway in this less-stringent use case. In the attack and change control use cases, you need to constantly monitor critical assets to identify dangerous situations. But to be compliant you basically need to assess devices quarterly or so. As long as you are collecting and parsing event logs on protected devices in a secure fashion (PCI Requirement 10), you’re good. Well, in terms of compliance, but not necessarily actual security. To be clear, logging is good. It helps when you have this information during incident response or investigation, so we are happy that PCI and other compliance hierarchies mandate it.

PCI also specifically requires assessment after ‘significant’ change (Requirement 11.2.3), but what does that mean? That kind of nebulous verbiage both gives you the leeway to assess and monitor the devices when you want to, and it also gives the PCI council (and card brands) the leeway to string you up during a breach. Compliance mandates like PCI may also specify a more ‘continuous’ monitoring approach such as an IDS (Requirement 11.4), which is also a good practice. But remember – this use case isn’t about being secure – just meeting the base requirements expressly mandated by regulation and/or guidance. So putting up an IDS to monitor your perimeter and fire one alert meets the requirement. Compliance is great, right?

We will get down off the soapbox now. Smart security professionals realize that compliance is a means to an end. They can use the compliance mandate to free up budget for equipment and processes that also assist with the attack and change control use cases.

Data Sources

The data sources you use for compliance tend to be pretty consistent with the attack use case, though without the more sophisticated telemetry and forensic data to really figure out what happened:

• Assets: Your asset base is the fundamental data source for all use cases. At least that’s consistent – you need an ongoing discovery capability to detect new devices on your network, and then a mechanism for profiling and classifying them.
• Events & Logs: Pretty much everything can and should be logged as part of the compliance use case – including security gear, network infrastructure, identity sources, data center servers, and applications, among others. This is helpful to demonstrate that the controls in place work, which is the goal of this use case.
• Patches: Keeping a device up to date is typically mandated by compliance regulations, so you need to generate reports showing which devices were updated when.
• Configurations: Another aspect of compliance is implementing and maintaining secure configurations. You will need to document the posture of protected devices periodically. Differentials and history are less important because compliance is based on a point-in-time view at your infrastructure.
• Vulnerabilities: Mandates also require periodic vulnerability scans of protected devices. So you need to document what was scanned, what was found, and eventually what was fixed, if the scan showed clear deficiencies.
• Other Documentation: Some mandates also require periodic penetration tests and other less automated functions. So you need the ability to store this unstructured data in the CSM repository as well, if it will be used as a compliance automation platform.

Preparing for the Audit

As opposed to a more action-oriented decision flow, as you saw with the attack and change control use cases, compliance is all about using data to prepare for assessment. You know when you need to be ready – it’s not like auditors show up as mystery shoppers to surprise you. You also know the nature of the documentation you need to provide. Shame on you if you aren’t prepared for an audit, when you know exactly what’s expected and when you need to be ready to deliver it.

To help you prepare for an audit and make it as painless as possible, here is a streamlined process adapted from Mike’s Pragmatic CSO methodology.

1. Describe Your Security Program: Wait, what? What about blasting the auditor with all sorts of reports to convince them you know what you’re doing? There is plenty of time for that, but only after you provide context for your security program – specifically how your CSM capabilities provide an accurate and timely view of information needed to understand your compliance posture.
2. Address Past Deficiencies: This is probably not your first audit, so you need to update the auditor on how you addressed previous findings. Here you can leverage your CSM platform to search for specifics and substantiate fixes for issues pointed out in the last assessment. One of the best ways to build your credibility with the assessor is to own your past mistakes and prove that you have fixed things.
3. Substantiate Your Controls: Now you can work through the data, showing the assessor that you have implemented the necessary controls effectively. This documentation should be pretty straightforward to generate, given that CSM platforms have tons of pre-built reporting templates to relate collected data to the requirements of the leading mandates and regulations.
4. Improve your monitoring efforts: Compliance is an overhead function, so you should be focused on continuous improvement. Learn from each audit how to more effectively package and present your data. Get a feel for where you need additional information, or perhaps where your existing collection efforts are overkill. Use these lessons to optimize your monitoring environment for this use case.
5. Get back to work: The thing about compliance is that it doesn’t really help you protect your data or meet the other objectives of your security program. The less time you spend preparing for an audit, and the sooner you can get it finished, the more time you can spend on other more productive aspects of your job. Compliance is table stakes, so you cannot afford to neglect it, but the more time you spend on it, the less you have to taking care of other business and ensure security.

We have now covered the major use cases for Continuous Security Monitoring. All that’s left is to implement the technology and automation needed to implement Continuous Security Monitoring, in a matter that will achieve your use cases – without breaking the bank.