Tag Archives: TTP

TTP-Based Threat Hunting – Why and How?

In its simplest definition, threat hunting is a process to identify whether adversaries reached to the organization’s network or not.

Despite many precautions taken at the perimeter level and many technologies used, breaches cannot be prevented. As a result of this situation, technologies to detect whether an attacker is inside have also come to the fore in recent years. EDRs and NDRs are mostly developed and used for detecting and they use many different methods for this.

Pyramid of Pain

In the event of a breach, the most important way to lower dwell time is to implement a regular and continuous threat hunting process. Earlier, as discussed in pyramid of pain, there are several methods for threat hunting like using signatures, IoCs, anomaly detection or TTPs.

A signature can be IP addresses, domains, or file hashes about the threat actor but as you can see above, they are at the bottom of the pyramid. Because they can be changed very easily by the attacker and these information mostly include false positives. When attackers register a new domain, or get a new IP address, it will be a 0-day for the organization and will be impossible to detect the attack via IoC sweep.

Therefore, using the attackers’ TTPs for threat hunting will give much more accurate results. Attackers do not change the techniques that they are using frequently, especially if they have been successful before with these techniques. The MITRE ATT&CK framework is the best way for this technique. Many organizations have adapted their infrastructure to miter or continue to work on this issue. If they haven’t started this yet, they should start as soon as possible.

Threat Intelligence: For a better and continuous threat hunting, threat intelligence is essential. There are lots of techniques and tactics in Att&ck and analysts must decide with threat intel where to start. For a start, it may be a good method to start by identifying the actors that will threaten them depending on the country, region and sector of the organization. This process will prioritize TTPs for hunting. It must be ensured that the threat intel provides this information up-to-date.

Developing Hypotheses: After prioritizing the TTPs for hunting, next step is to creating the hypotheses. This step means determining the data that should be collected to detect the adversarial behavior. According to the required data, it is determined with which security controls the detection should be made.

At this stage, also there is a need to make a gap analysis to be ensure that we can detect all the related activity. If necessary, other security controls should be added. This process can be done with security validation tools like Verodin, since In Verodin all tests and reports are Att&ck based. Hunt teams should correct both they can get needed logs from every piece of the network and these logs are sent to SIEM regularly. So Verodin also should be used for these steps.

This data selection phase also provides to use SIEM more effective. By understanding the adversarial techniques, organizations can reduce the log size by reducing the volume of data collected. This will also allow analysts to encounter fewer false positive alerts and saves time.

The most annoying thing in SIEM administration is the volume of data. Thus, while we are getting data from host or network security controls, we should carry out that we do not send useless data to the SIEM. Be careful about both EDR and especially NDR solutions can create huge amount of data.

CTI does not mean Fraud Detection

Organizations invests more and more to security tools, breach statistics keep increasing. About ten years ago and more, attackers were mostly alone, and were using basic tools, so it was easier to block them. But with the advanced techniques and tools, and the groups that came together to attack, made these attacks more difficult to block. There was no such thing as intelligence on our agenda. Some basic blacklists and virus databases were enough against most of the attackers.

CTI (Cyber Threat Intelligence) has become indispensable nowadays. We need more and more information about attackers day by day to gain advantage in this fight. At the same time, we see that a lot of people confuse threat intelligence with fraud. People seem really confused about what to expect from threat intelligence. In this post, I try to mention the needs and usage for CTI.

IoCs: Of course, IoCs are one of the most important things that we are waiting from a CTI product. We are feeding our tools with IoCs and this is the simplest thing for our security intelligence. It is possible to find open source IoCs on many historical threats on the internet. Our expectation from a CTI product should be that it gives us the latest IOCs on threats. While evaluating a CTI tool, it should be observed how much IOC it gives compared to its competitors. Some CTI vendors are mostly using Open IoCs, so it is important to check this value before paying money. Meanwhile, the accuracy of the IOCs is also an issue that should not be overlooked. There will be no point in pushing so many wrong IoCs into our systems every day, even those false positive IoC will cause us to waste time. And time is the most important value in a battle.

TTPs: According to Pyramid of Pain – we discussed in the related post deeply – TTPs are the most valued information for defenders. Sun Tzu says that “if you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle.” Of course this is very meaningful. If you do not know what tools, techniques and tactics your enemies are using, it d be very difficult to win a battle. For a defender, the most valuable information are these TTPs and tools that the enemy is using. From a CTI vendor, this must be one of your most important expectations.

Threat Groups: As mentioned before, attackers now works together, they come together and join forces. And while a group is successful on technique with specific tools and malwares, they rarely change these TTPS and tools. So, it is very important to know who is targeting your geography, country and sector. With these information, organizations get really useful IOCs for themselves, and can design their defense according to these attackers’ TTPs. According to this, maybe tracking the threat groups are also the most important thing for the first two bullets (IoCs and TTPs). You can take random IOCs and install them on your systems, but this is never the same as working with the information of attackers you know who they are.

Vulnerabilities: are critical because attackers use these vulnerabilities to infiltrate. It is vital to be aware of vulnerabilities as quickly as possible after they appear. Meanwhile, the information whether these vulnerabilities are exploitable or not, and their criticality and knowledge of affected systems should also be among the things you expect from CTI. Of course, you need a proactive patch management to use these information in success.

Dark Web Tracking: Every day, a lot of information about companies is offered for sale on the dark web or different attackers and groups come together by communicating here. It is not possible to track all forums and portals in dark web continuously for a security team. One of the expectations from the CTI should be the constant monitoring of the dark web and access to information about threats to the organization.

CTI is not Fraud Detection: Fraud is an important subject to save customers our and users. There are many fraud techniques that fraud teams need to be aware of but CTI is not fraud. As mentioned at the beginning, people seem really confused about what CTI and fraud are. Some CTI vendors provide fraud data to their customer. It is undisputed very valuable. But a CTI product should not be evaluated solely on the fraud information obtained. For a good CTI investment, the above issues should be evaluated.