Trends are interesting since they could tell you where things are going.
I do believe in studying history and behaviors in order to figure out where things are going on, so that every Year my colleagues from Yoroi and I spend several weeks to study and to write what we observed during the past months writing the Yoroi Cybersecurity Annual Report (freely downloadable from here: Yoroi Cybersecurity Report 2019).
The Rise of Targeted Ransomware
2019 was a breakthrough year in the cyber security of the European productive sector. The peculiarity of this year is not strictly related to the number of hacking attempts or in the malware code spread all over the Internet to compromise Companies assets and data but in the evolution and the consolidation of a new, highly dangerous kind of cyber attack. In 2019, we noticed a deep change in a consistent part of the global threat landscape, typically populated by States Sponsored actors, Cyber-Criminals and Hack-tivists, each one having some kind of attributes, both in motivations, objectives, methods and sophistications.
During the 2019 we observed a rapid evolution of Cyber Crime ecosystems hosting a wide range of financially motivated actors. We observed an increased volume of money-driven attacks compared to previous years. But actors are also involved in cyber-espionage, CEO frauds, credential stealing operations, PII (Personally Identifiable Information) and IP (Intellectual Property) theft, but traditionally much more active in the so called “opportunistic” cyber attacks. Attacks opportunistically directed to all the internet population, such as botnets and crypto-miners infection waves, but also involved in regional operations, for instance designed to target European countries like Italy or Germany as branches of major global-scale operations, as we tracked since 2018 with the sLoad case and even earlier with the Ursnif malware propagations waves.
In 2019 like what happened in 2018, Ransomware attacks played a significant role in the cyber arena. In previous years the whole InfoSec community observed the fast increase in o the Ransomware phenomenon, both in term of newborn ransomware families and also in the ransom payment options, driven by the consolidation of the digital cryptocurrencies market that made the traditional tracking techniques – operated by law enforcement agencies – l less effective due to new untrackable crypto currencies. But these increasing volumes weren’t the most worrying aspect we noticed.
Before 2019, most ransomware attacks were conducted in an automated, mostly opportunistic fashion: for instance through drive by download attacks and exploit kits, but also very frequently using the email vector. In fact, the “canonical” ransomware attacks before 2019 were characterized by an incoming email luring the victim to open up an attachment, most of the times an Office Document, carefully obfuscated to avoid detection and weaponized to launch some ransomware malware able to autonomously encrypt local user files and shared documents.
During 2019, we monitored a deep change in this trend. Ransomware attacks became more and more sophisticated. Gradually, even major cyber-criminal botnet operators, moved into this emerging sector leveraging their infection capabilities, their long term hacking experience and their bots to monetize their actions using new malicious business models. Indeed, almost every major malware family populating the cyber criminal landscape was involved in the delivery of follow up ransomware within infected hosts. A typical example is the Gandcrab ransomware installation operated by Ursnif implants during most of 2019. But some criminal groups have gone further. They set the threat level to a new baseline.
Many major cyber criminal groups developed a sort of malicious “RedTeam” units, lest call them “DarkTeams”. These units are able to manually engage high value targets such as private companies or any kind of structured organization, gaining access to their core and owning the whole infrastructure at once, typically installing ransomware tools all across the network just after ensuring the deletion of the backup copies. Many times they are also using industry specific knowledge to tamper with management networks and hypervisors to reach an impressive level of potential damage.
Actually, this kind of behaviour is not new to us. Such methods of operations have been used for a long time, but not by such a large number of actors and not with such kind of objectives. Network penetration was in fact a peculiarity of state sponsored groups and specialized cyber criminal gangs, often threatening the banking and retail sectors, typically referenced as Advanced Persistent Threats and traditionally targeting very large enterprises and organizations.
During 2019, we observed a strong game change in the ransomware attacks panorama.
The special “DarkTeams” replicated advanced intrusion techniques from APT playbooks carrying them into private business sectors which were not traditionally prepared to deal with such kinds of threats. Then, they started to hit organizations with high impact business attacks modeled to be very effective for the victim context. We are facing the evolution of ransomware by introducing Targeted Ransomware Attacks.
We observed and tracked many gangs consolidating the new Targeted Ransomware Attacks model. Many of them have also been cited by mainstream media and press due to the heavy impact on the business operation of prestigious companies, such as the LockerGoga and Ryuk ransomware attacks, but they only were the tip of the iceberg. Many other criminal groups have consolidated this kind of operations such as DoppelPaymer, Nemty, REvil/Sodinokibi and Maze, definitely some of the top targeted ransomware players populating the threat landscape in the last half of 2019.
In the past few months we also observed the emergence of a really worrisome practice by some of these players: the public shame of their victims. Maze was one of the first actors pionering this practice in 2019: the group started to disclose the name of the private companies they hacked into along with pieces of internal data stolen during the network intrusions.
The problem rises when the stolen data includes Intellectual Property and Personal Identifiable Information. In such a case the attacker leaves the victim organization with an additional, infaust position during the cyber-crisis: handling of the data breach and the fines disposed by the Data Protection Authorities. During 2020 we expect these kinds of practices will be more and more common into the criminal criminal ecosystems. Thus, adopting a proactive approach to the Cyber Security Strategy leveraging services like Yoroi’s Cyber Security Defence Center could be crucial to equip the Company with proper technology to acquire visibility on targeted ransomware attacks, knowledge, skills and processes to spot and handle these kind of new class of threats.
Zero-Day Malware
Well Known threats are always easier to be recognized and managed since components and intents are very often clear. For example a Ransomware, as known today, performs some standard operations such as (but not limited to): reading file, encrypting file and writing back that file. An early discovery of known threat families would help analysts to perform quick and precise analyses, while unknown threats are always difficult to manage since analysts would need to discover firstly the intentions and then bring back behaviour to standard operations. This is why we track Zero-Day Malware. Yoroi’s technology captures and collects samples before processing them on Yoroi’s shared threat intelligence platform trying to attribute them to known threats.
As part of the automatic analysis pipeline, Yoroi’s technology reports if the malicious files are potentially detected by Anti-Virus technologies during the detection time. This specific analogy is mainly done to figure-out if the incoming threat would be able to bypass perimetral and endpoint defences. As a positive side effect we collect data on detected threats related to their notoriety. In other words we are able to see if a Malware belonging to a
threat actor or related to specific operation (or incident) is detected by AV, Firewall, Next Generation X and used endpoints.
In this context, we shall define what we mean for Zero-Day Malware. We call Zero-Day malware every sample that turns out to be an unknown variant of arbitrary malware families. The following image (Fig:1) shows how most of the analyzed Malware is unknown from the InfoSec community and from common Antivirus vendors. This finding supports the even evolving Malware panorama in where attackers start from a shared code base but modify it depending on their needed to be stealth.
The reported data are collected during the first propagation of the malicious files across organizations. It means Companies are highly exposed to the risk of Zero-Day malware. Detection and response time plays a central role in such cases where the attack becomes stealth for hours or even for days.
Along with the Zero-Day malware observation, most of the known malware at time of delivery have not so high chances of being blocked by security controls. The 8% of the malware is detected by few AV engines and only 33% is actually well identified at time of attack. Even the so-called “known malware” is still a relevant issue due to its capability to maintain a low detection rate during the first infection steps. Indeed only less than 20% of analyzed samples belonging to “not Zero-Day” are detected by more than 15 AV engines.
Drilling down and observing the behavioural classification of the intercepted samples known by less than 5 AntiVirus engines at detection time, we might appreciate that the “Dropper” behaviour (i.e. the downloading or unpacking of other malicious stages or component) lead the way with 54% of cases, slightly decreasing since the 2018. One more interesting trend in the analyzed data is the surprising decrease of Ransomware behaviour, dropping from 17% of 2018 to the current 2%, and the bullish raise of “Trojan” behaviours up to 35% of times, more than doubled respect to the 15% of 2018.
This trend endorses the evidence that ransomware attacks in 2019 begun to follow a targeted approach as described in the “The Rise of Targeted Ransomware” section.
A reasonable interpretation of the darkling changes on these data, could actually conform with the sophistication of the malware infection chain discussed in the previous section. As a matter of fact, many of the delivered malware are actually a single part of a more complex infection chain. A chain able to install even multiple families of malware threats, starting from simple pieces of code behaving like droppers and trojan horses to grant access to a wider range of threats.
This trend gets another validation even in the Zero-Day malware data set: the samples likely unknown to Info.Sec. community – at the time of delivery – substantially shifted their distribution from previous years. In particular, Ransomware behaviour detections dropped from 29% to 7% in 2019, and Trojan raised from 28% to 52% of cases, showing similar macro variations.
If you want to read more details on “DarkTeams” and on what we observed during the past months, please feel free to download the full report HERE.
