According to Kaspersky Global IT Risk Report 2016 (14), the top causes for the most costly data breaches are based on old attacks that are evolving over time, which are in the following order:

• Viruses, malware, and trojans
• Lack of diligence and untrained employees
• Phishing and social engineering
• Targeted attack
• Crypto and ransomware

Although the top three in this list are old suspects and very well-known attacks in the cybersecurity community, they are still succeeding, and for this reason they are still part of the current cybersecurity challenges. The real problem with the top three is that they are usually correlated to human error. As explained before, everything may start with a phishing email that uses social engineering to lead the employee to click on a link that may download a virus, malware, or Trojan. In the last sentence, we covered all three in a single scenario.

The term targeted attack (or advanced persistent threat) sometimes is not too clear for some individuals, but there are some key attributes that can help you identify when this type of attack is taking place. The first and most important attribute is that the attacker has a specific target in mind when he/she starts to create a plan of attack. During this initial phase, the attacker will spend a lot of time and resources to perform public reconnaissance to obtain the necessary information to carry out the attack. The motivation behind this attack is usually data exfiltration, in other words, stealing data. Another attribute for this type of attack is the longevity, or the amount of time that they maintain persistent access to the target's network. The intent is to continue moving laterally across the network, compromising different systems until the goal is reached.

One of the greatest challenges in this area is to identify the attacker once they are already inside the network. The traditional detection systems such as Intrusion Detection Systems (IDS) may not be sufficient to alert on suspicious activity taking place, especially when the traffic is encrypted. Many researchers already pointed out that it can take up to 229 days between the infiltration and detection (15). Reducing this gap is definitely one of the greatest challenges for cybersecurity professionals.

Crypto and ransomware are emerging and growing threats that are creating a whole new level of challenge for organizations and cybersecurity professionals. In May 2017, the world was shocked by the biggest ransomware attack in history, called Wannacry. This ransomware exploited a known Windows SMBv1 vulnerability that had a patch released in March 2017 (59 days prior to the attack) via MS17-010 (16) bulletin. The attackers used an exploit called EternalBlue that was released in April 2017, by a hacking group called Shadow Brokers. According to MalwareTech (18), this ransomware infected more than 400,000 machines across the globe, which is a gigantic number, never seen before in this type of attack. One lesson learned from this attack was that companies across the world are still failing to implement an effective vulnerability management program, which is something we will cover in more detail in Chapter 15, Vulnerability Management.

It is very important to mention that phishing emails are still the number one delivery vehicle for ransomware, which means that we are going back to the same cycle again, educate the user to reduce the likelihood of successful exploitation of human factor via social engineering, and have tight technical security controls in place to protect and detect.