4Security operations, by their nature, are a highly technical and complex set of activities that demand SOC teams deeply understand the threats they face and the attack vectors they protect. Gaining complete coverage was challenging, and without architecture or standards to map their efforts, a comprehensive visibility of threats was impossible.
MITRE has changed this by publishing ATT&CK as an open framework and knowledge base of cyber attacks. It’s readily available to security analysts and contains a complete list of adversary tactics and techniques, all of which are based on real-world telemetry and reports MITRE has gathered over the years. The framework has a scientific basis in observation, making it the perfect way to orient the efforts of the SOC.
Let’s look at how tools are now evolving to adopt MITRE ATT&CK and how this changes the operations game to place defenders on a level playing field with attackers.
Understanding MITRE ATT&CK
ATT&CK can be used to underpin the cyber defence processes your security operations team uses, combining observed adversary tactics and techniques into a common language so that monitoring and response efforts can be quickly informed by security information in the repository. It bolsters detection and Incident Response (IR) both as a management and technical framework by allowing responders to identify and classify incidents while providing the details on what artefacts threat hunters should be looking for. Security managers can use ATT&CK to map current detection capability and security controls while identifying gaps in security architecture to highlight where the SOC team may need to develop rules and visibility further.
ATT&CK’s structured approach to classifying techniques maps at a high level to the cyber “kill chain” concept in that it begins with the categories of reconnaissance and resource development, and initial access, and then encompasses the various phases of a successful attack through to command and control, exfiltration and impacts. Each category of tactics contains a list of techniques and sub-techniques (varying iterations of methods), each explained in terms of the technology used to achieve it, the threat actors commonly associated with using it and any recommended mitigations.
MITRE keeps ATT&CK up to date with the most recent technical details so that any changes to observed adversary methods are quickly available to framework subscribers, to ensure SOC teams can develop new detection rules speedily and efficiently. One additional element of the ATT&CK framework that’s vitally important to SOC teams and security managers alike is that it describes mitigations for each technique so operators know how to respond.
Each technique and sub-technique included in MITRE ATT&CK contains a list of recommendations of countermeasures. To better protect the enterprise, the nature of these measures range from specific controls through to broader risk management strategies.
“Adversaries may use brute force techniques to gain access to accounts when passwords are unknown or when password hashes are obtained. Without knowledge of the password for an account or set of accounts, an adversary may systematically guess the password using a repetitive or iterative mechanism. Brute forcing passwords can take place via interaction with a service that will check the validity of those credentials or offline against previously acquired credential data, such as password hashes.”
The corresponding ATT&CK mitigation strategies suggested for a Brute Force attack include::
- Account use policies: Set account lockout policies after a certain number of failed login attempts to prevent passwords from being guessed. Too strict a policy may create a denial of service condition and render environments un-usable, with all accounts used in the brute force being locked-out;
- Multi-factor Authentication: Use multi-factor authentication. Where possible, also enable multi-factor authentication on externally facing services;
- Password Policies: Refer to NIST guidelines when creating password policies; and
- User Account Management: Proactively reset accounts that are known to be part of breached credentials either immediately, or after detecting brute force attempts.
SOC teams can also refer to this entry for detection recommendations, and setting rules to identify such behaviour with their monitoring tools – including their Security Information and Event Management (SIEM) system.
For brute force attacks, SOC teams can monitor both system and application logs for failures against valid accounts, especially if authentication failures are high in volume or unusually frequent, indicating there may be a brute force attack underway. SOC teams can also monitor for failed authentication attempts across several accounts at once, which may indicate password spraying.
ATT&CK in Practice
SOC technologies, such as SIEM and Security Analytics platforms, that incorporate the MITRE ATT&CK framework as a standard reference model, can rapidly prioritise threats and assist SOC analysts in deciding which alarms to tackle first. Given there are now over 500 techniques in ATT&CK, having the SIEM automatically profile and report on activity patterns in this way, allows SOC teams to determine the stage of the attack lifecycle that a detected event relates to, and so how successful that attack may be.
As you can see in the Summary Dashboard shown in Figure 1 (captured from the forthcoming release of Huntsman Security’s NextGen SIEM), the top 10 threat targets and techniques can be easily highlighted for investigation, while at the same time serving as a rapid reference monitor for SOC management to understand where to best focus their response efforts. By allowing analysts to look at attacks by type and observed technique priority, they can streamline their response workflows. At a macro level also, the team is less likely to miss crucial detections during busy periods of high alert volumes.
Analysts can quickly drill further into the MITRE data, expose the source of an alert and deploy the incident response team to investigate and shut it down if it’s a real attack.