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Ransom DDoS Extortion On the Rise Again
A recent report from researchers at Proofpoint showed that ransom distributed denial-of-service (DDoS) extortions are on the rise again.
In the blog post “Ransom DDoS Extortion Actor 'Fancy Lazarus' Returns,” researchers at Proofpoint reported that since May 21, 2021, they've observed renewed DDoS extortion activity targeting an increasing number of industries by the threat group known as "Fancy Lazarus." In a DDoS attack, a system (website, network, application server, DNS server, and individual IP) is flooded with data requests in a bid to shut it down.
“The ransom distributed denial of service extortion threat actor known as ‘Fancy Lazarus’ is back, taking aim at an increasing number of industries, including the energy, financial, insurance, manufacturing, public utilities, and retail sectors,” researchers at Proofpoint said. “The actor [Fancy Lazarus] took over a month-long break from April to May 2021 before returning with new campaigns that include some changes to the group’s tactics, techniques, and procedures ….”
According to researchers at Proofpoint, the threat group’s latest campaign changes the group’s name to Fancy Lazarus from previous names such as “Lazarus,” “Lazarus Group,” and “Armada Collective.” The researchers found no connection between this ransom DDoS extortion group and the advanced persistent threat (APT) actors with the same names.
Ransom DDoS Extortion Prevalence
On November 1, 2019, CERT NZ reported that it received reports relating to an extortion campaign targeting companies within the financial sector in New Zealand. The extortion campaign, CERT NZ said, involved two phases. The first phase involved an email stating the name of the extortionist, the name of the target company, the deadline when the major DDoS attack will occur and the demand for a ransom to prevent it.
The second phase, according to CERT NZ, involved a demonstrative DDoS attack (typically lasting 30 minutes) against an IP address belonging to the companies’ network. CERT NZ said the DDoS techniques used in the demonstrative DDoS attack, include targeting services using the following protocols:
Hyper Text Transfer Protocol (HTTP)
Web Service Dynamic Discovery (WSD)
Apple’s Remote Management Service (ARMS)
Simple Service Discovery Protocol (SSDP)
Network Time Protocol (NTP)
Domain Name System (DNS)
Lightweight Directory Access Protocol (LDAP)
SYN and Internet Control Message Protocol (ICMP)
On November 15, 2019, researchers at Akamai said multiple companies have reported receiving an email demanding 2 bitcoins. Akamai said the extortion email contains a threat that if payment isn’t made before the deadline expires, the price increases by 1 bitcoin and the targeted DDoS attack will start.
“Shortly after a customer received one of these extortion emails, Akamai observed a 30Gbps attack (at peak) originating from a globally distributed botnet, where each IP sent a fraction of the overall traffic,” Akamai said. “The attackers were abusing DNS, Apple Remote Management Service (ARMS), CLDAP, TFTP, PortMap, and WS-Discovery (WSD), across the UDP protocol.”
In August 2020, the Federal Bureau of Investigation (FBI) issued an alert warning that thousands of organizations in multiple industries across the globe were targeted in the ransom DDoS extortion campaign similar to the ransom DDoS extortion campaign described by Akamai and CERT NZ. According to the FBI, DDoS "demonstration" launched by the threat group varied across institutions with some targeting a single IP address and others targeting multiple IP addresses, as well as variable peak volumes and attack length.
In the August 2020 blog post "Ransom Demands Return: New DDoS Extortion Threats From Old Actors Targeting Finance and Retail," researchers at Akamai said they’ve observed ransom DDoS attacks peak at almost 200 Gb/sec, utilizing ARMS, DNS Flood, GRE Protocol Flood, SNMP Flood, SYN Flood, and WSDiscovery Flood attacks as their main vectors.
Teresa Walsh, global head of intelligence at the Financial Services Information Sharing and Analysis Center (FS-ISAC), a cybersecurity consortium of nearly 7,000 financial companies told the Wall Street Journal last February that the global nature of the targets of the ransom DDoS extortion campaign was alarming, citing victims in North America, Latin America, Europe, the Middle East, Africa, and Asia-Pacific.
“After about four or five members raised their hands to say that they were seeing similar activity [ransom DDoS extortion], that’s when we started diving into a potential campaign against our members,” said Walsh. “This accumulated week upon week. Even months later, we were still seeing extortion emails coming through, and short-lived attacks,” Ms. Walsh said.
Ransom DDoS Extortion Campaign Modus Operandi
According to Proofpoint researchers, the ransom DDoS extortion campaign modus operandi always begins with sensational emails. The researchers said the extortion emails contain the following:
It’s important to note that DDoS attack against websites, networks, application servers, DNS servers, and individual IPs is now preventable with a DDoS protection solution.
Rise of Ransomware Attacks in the Education Sector
The National Cyber Security Centre (NCSC), an organization of the UK Government that provides cybersecurity guidance and support, recently reported that it has continued to respond to an increased number of ransomware attacks against schools, colleges and universities in the UK.
“As of late May/June 2021, the NCSC is investigating another increase in ransomware attacks against schools, colleges and universities in the UK,” NCSC said. The NCSC previously highlighted an increase in ransomware attacks on the UK education sector during August/September 2020 and again in February 2021.
Ransomware and Its Impact
Ransomware is a type of malicious software (malware) that’s traditionally known to encrypt victims’ files, preventing victims to access these files. After file encryption, a ransom note is shown on the compromised computer informing the victim to pay a certain amount, typically in the form of cryptocurrency, for the decryption tool that would unlock the encrypted files.
More recently, ransomware operators threaten victims to release files stolen from the victim’s network in case of refusal to pay the ransom for the decryption tool. More ransomware operators have recently employed the double ransom tactic, in which, a victim is asked to pay two ransom payments.
The first ransom payment is for the decryption tool while the second ransom payment is for the non-publication of the files stolen from the victim’s network. Ransomware operators maintain “name and shame” websites on the darknet to name and shame ransomware victims who continue to refuse to pay ransom.
“In recent incidents affecting the education sector, ransomware has led to the loss of student coursework, school financial records …,” NCSC said. According to the NCSC, ransomware attacks in the education sector can have a devastating impact on organizations, with victims requiring a significant amount of recovery time to reinstate critical services, and these events can also be high profile in nature, with wide public and media interest.
An attack vector refers to the path or means in which an attacker gains access to an organization’s network to deliver a malware, in this case, a ransomware. According to the NCSC, ransomware attackers can gain access to a victim’s network through remote access systems, phishing emails, and other vulnerable software or hardware.
According to the NCSC, attackers gain access to victims’ networks through remote access systems such as remote desktop protocol (RDP) and virtual private networks (VPN). RDP is a proprietary protocol developed by Microsoft that allows employees working from home to access their office desktop computers or servers from another device over the internet.
The shift towards remote learning over the past year as a result of COVID-19 restrictions resulted in many organizations deploying VPN access as VPN is viewed as a secure way of accessing company networks and private resources. In recent years, multiple security vulnerabilities have been discovered in RDP and in a number of VPN appliances such as Citrix, Fortinet, Pulse Secure and Palo Alto.
According to the NCSC, phishing emails are frequently used by attackers to deploy ransomware. An attacker sends a phishing email – disguised as coming from a legitimate sender – to trick the email receiver to click a link or download an attachment, enabling the deployment of the ransomware into the email receiver’s computer.
Other Vulnerable Software or Hardware
According to the NCSC, unpatched or unsecure devices have commonly been used by ransomware attackers as an easy route into networks. An example of a software vulnerability exploited by ransomware attackers to install ransomware on a network is the vulnerability in Microsoft Exchange Servers.
The NCSC added that ransomware attackers have recently been observed sabotaging backup devices in order to make recovery more difficult; encrypting the entire virtual servers, and using scripting environments, for example, PowerShell, to easily deploy the ransomware.
Cybersecurity Best Practices
Here are some cybersecurity best practices as recommended by the NCSC that can be employed by organizations in the education sector in order to prevent and mitigate the effects of ransomware attacks:
Keep up-to-date and tested offline backups.
As ransomware attackers have been known for sabotaging internet-exposed backup devices in order to make recovery more difficult, it’s important to keep offline backups to recover from a ransomware attack.
Secure remote access systems (RDP and VPN) via strong passwords, multi-factor authentication (MFA), and applying patches in a timely manner.
Implement effective vulnerability management and patching procedures.
Implement the following mechanisms to prevent phishing attacks: making it harder for email from your domains to be spoofed by employing the anti-spoofing controls, filtering or blocking incoming phishing emails, training your users particularly in the form of phishing simulations, and building a culture where users can report phishing attempts.
Canada Post Becomes the Latest Victim of Supply Chain Attack
Canada Post recently announced that it fell victim to a supply chain attack, resulting in a data breach relating to nearly a million receiving customers.
A supply chain attack, also known as a third-party attack, happens when an attacker infiltrates your organization’s system through an outside partner or supplier with access to your organization’s system.
In a press statement released last May 26th, Canada Post said that it was informed last May 19th by one of its suppliers, Commport Communications, that this supplier suffered a ransomware attack and that said ransomware attack compromised Canada Post customers.
Commport Communications’ electronic data interchange (EDI) solution is used by Canada Post to manage the shipping manifest data of large parcel business customers. Shipping manifests typically include sender and receiver contact information such as the names and addresses of the business sending the item and the customer receiving it.
“In all, the impacted shipping manifests for the 44 commercial customers contained information relating to just over 950 thousand receiving customers,” Canada Post said.
Canada Post added that the impacted shipping manifests were from July 2016 to March 2019 and that the vast majority (97%) contained the name and address of the receiving customer, while the remainder (3%) contained an email address and/or phone number.
“We are now working closely with Commport Communications and have engaged external cyber security experts to fully investigate and take action,” Canada Post said. “We are proactively informing the impacted business customers and providing the information and support necessary to help them determine their next steps. As well, the Office of the Privacy Commissioner has been notified.”
According to Canada Post, in November 2020, Commport Communications notified Innovapost, Canada Post's IT subsidiary, of a potential ransomware issue. Canada Post said that Commport Communications advised at that time that there was no evidence to suggest any customer data had been compromised.
In December 2020, the group behind the ransomware called “Lorenz” posted on its data leak site that they had breached Commport Communications during a ransomware attack.
Lorenz ransomware is a relatively new actor in the ransomware field. Similar to other ransomware, Lorenz encrypts victims’ files and demands from victims ransom for the decryption tool that would unlock the encrypted files. Michael Gillespie of ID Ransomware told BleepingComputer that the Lorenz ransomware and older ransomware known as “ThunderCrypt” have the same encryptor. It isn’t clear whether Lorenz and ThunderCrypt are operated by the same group or if the newer ransomware purchased the source code of the older ransomware to create its own variant.
Similar to other ransomware, Lorenz ransomware steals victims’ files. And similar to other ransomware groups, the group behind Lorenz ransomware maintains a website in which password-protected archives of stolen files are published.
According to BleepingComputer, the group behind Lorenz ransomware is different from other ransomware groups as this group first sells the stolen data to other threat actors or possible competitors. In case no one buys the stolen data and the victim refuses to pay, the group behind Lorenz ransomware releases the password for the password-protected data leak archive in order to make the stolen data available to anyone who downloads the files.
Another peculiar characteristic of the group behind Lorenz ransomware is that the group also sells access to the victim's internal network along with the data. Access to the victim's internal network, for some threat actors, is more valuable than the data.
“Like other human-operated ransomware attacks, Lorenz will breach a network and spread laterally to other devices until they gain access to Windows domain administrator credentials,” BleepingComputer said. “While spreading throughout the system, they will harvest unencrypted files from victims' servers, which they upload to remote servers under their control.”
Cybersecurity Best Practices
Many human-operated ransomware attacks gain initial access to their victims’ networks by brute-forcing RDP (Remote Desktop Protocol) – a network communications protocol developed by Microsoft that allows users to remotely connect to another computer.
RDP servers that use weak username and password combination, without multi-factor authentication (MFA), without virtual private networks (VPNs), and without other security protections are easily accessed by attackers through brute force attack – the trial and error method of guessing the correct username and password combination. Threat actors have also been known to use RDP for lateral movement. With RDP, attackers can move laterally through the network without the need for credentials.
RDP servers can be protected from brute force attacks by using a strong username and password combination, MFA, and VPN. Attackers easily scan for internet-exposed RDP through the default RDP port: TCP 3389. Changing the RDP default RDP port essentially hides your organization’s RDP server from the attackers’ scanning efforts.
In the blog post "Human-operated ransomware attacks: A preventable disaster," Microsoft 365 Defender Threat Intelligence Team recommends practicing the principle of least privilege and maintaining credential hygiene. “Avoid the use of domain-wide, admin-level service accounts,” Microsoft 365 Defender Threat Intelligence Team said. “Enforce strong randomized, just-in-time local administrator passwords. Use tools like LAPS.”
Top 3 Tools Used by Cyberattackers in 2020 and Early 2021
Three legitimate pentesting tools – PowerShell, Cobalt Strike, and PsExec – topped the list of tools used by cyberattackers in breaking into victims’ networks in 2020 and early 2021, according to Sophos’ report based from frontline threat hunters and incident responders.
In the report “The Active Adversary Playbook 2021,” Sophos found that PowerShell, followed by Cobalt Strike, and PsExec are the top 3 tools used by cyberattackers in 2020 and early 2021.
PowerShell, Cobalt Strike, and PsExec are legitimate tools used by IT administrators and security professionals for penetration testing, also known as pentesting – an authorized simulated cyberattack against an organization’s computer system to examine exploitable vulnerabilities. Threat actors, however, have been using these same pentesting tools to break into victims’ networks.
According to Sophos report, correlations emerge among the top 3 tools found in victims’ networks. The report added that when PowerShell is used in an attack, Cobalt Strike was seen in 58% of cases, and PsExec in 49% of cases; Cobalt Strike and PsExec were used together in 27% of attacks; and the combination of Cobalt Strike, PowerShell, and PsExec occurs in 12% of all attacks.
PowerShell is a task-based command-line shell and scripting language designed for system administration in the Windows operating system. Attackers use PowerShell to conduct a number of malicious activities, including executing malicious code, creating new tasks on remote machines, identifying configuration settings, pulling Active Directory information from the target environment, evading defenses, exfiltrating data, and executing other commands.
The malicious software called “Emotet” has used PowerShell to retrieve the malicious payload and download additional resources like Mimikatz – ranked fourth in the tools used by cyberattackers in 2020 and early 2021 in the Sophos report. Mimikatz is capable of obtaining plaintext Windows account logins and passwords.
PsExec is a free Microsoft tool that is used by IT administrators to execute a program on another computer. This tool has been used by attackers to download or upload a file over a network share.
Cobalt Strike is a commercially available pentesting tool that’s marketed as "adversary simulation software designed to execute targeted attacks and emulate the post-exploitation actions of advanced threat actors."
This commercial pentesting tool was developed by researcher Raphael Mudge in 2012. This tool was recently acquired by HelpSystems. In 2020, the source code of Cobalt Strike version 4.0 was leaked to the public. Adversaries often use the purchased and pirated/cracked versions of Cobalt Strike.
This tool is capable of executing a payload on a remote host with PowerShell and using PsExec to execute a payload on a remote host. Cobalt Strike’s Beacon is used to perform actions such as collecting information on process details, reaching out to the command-and-control server on an arbitrary and random interval, breaking large data sets into smaller chunks for exfiltration, and capturing screenshots.
The tools PowerShell and Cobalt Strike were used in the recently unraveled supply chain attack on SolarWinds.
In the SolarWinds supply chain attack, attackers compromised the code update of SolarWinds’s product Orion, which gave the attackers the opportunity to attack customers that applied the compromised SolarWinds Orion update. The SolarWinds supply chain attack victims include cybersecurity firm FireEye and Microsoft.
In the blog post "Raindrop: New Malware Discovered in SolarWinds Investigation," security researchers at Symantec reported that the malicious software (malware) called "Raindrop" enabled the delivery of Cobalt Strike into the victims’ networks. Security researchers at Symantec reported that in the victim’s computer where the Raindrop malware was found, it was observed that several days later, PowerShell commands were executed on that computer, attempting to execute further instances of Raindrop malware on additional computers in the organization.
The top 3 tools, PowerShell, Cobalt Strike, and PsExec, used by cyberattackers in 2020 and early 2021 were all used by the group behind the ransomware called “DoppelPaymer.” Similar to modern-day ransomware, DoppelPaymer encrypts victims’ files, locking these victims out from accessing their files, and demands from victims to pay ransom in exchange for the decryption tool that would unlock the encrypted files.
Similar to other modern ransomware, the group behind DoppelPaymer threatens victims with the publication of their stolen files on the data leak site as part of the ransomware’s extortion scheme. In DoppelPaymer ransomware, PowerShell, Cobalt Strike, PsExec, and Mimikatz – ranked fourth in the tools used by cyberattackers in 2020 and early 2021 in the Sophos report – were used to stealing credentials, moving laterally inside the network, and executing different commands.
In the blog post "Ransomware groups continue to target healthcare, critical services; here’s how to reduce risk," Microsoft 365 Defender Threat Intelligence Team said that defenders should pay attention to malicious “PowerShell, Cobalt Strike, and other penetration-testing tools that can allow attacks to blend in as benign red team activities.”
“Security teams can defend their organization by monitoring and investigating suspicious activity,” Sophos in the “The Active Adversary Playbook 2021” said. “The difference between benign and malicious is not always easy to spot. Technology in any environment, whether cyber or physical, can do a great deal but it is not enough by itself. Human experience and the ability to respond are a vital part of any security solution.”
Cybersecurity Best Practices Against DarkSide Ransomware
The ransomware called “Darkside” wreaked havoc lately, with Colonial Pipeline, which operates the largest fuel pipeline in the U.S., as its latest high-profile victim.
Colonial Pipeline became aware of the ransomware attack last May 7, forcing the company to shut down its operations. The company was able to restart its operations last May 12.
A report from Bloomberg showed that Colonial Pipeline paid within hours after the attack the group behind Darkside ransomware nearly $5 million. According to the Bloomberg report, once nearly $5 million was paid, the group behind Darkside ransomware gave the decryption tool for Colonial Pipeline to restore its disabled computer network.
The decryption tool, however, was so slow that the Colonial Pipeline continued using its own backups to help restore the system, the report said.
What Is DarkSide Ransomware?
DarkSide ransomware is a ransomware-as-a-service (RaaS) in which the ransomware developers receive a share of the proceeds from the cybercriminal actors who deploy the ransomware, known as “affiliates.”
This ransomware was first observed in the wild in August 2020 and has been known to target high-revenue organizations. Similar to modern ransomware, DarkSide ransomware encrypts victims’ files and demands from victims ransom payment in exchange for the decryption tool that would unlock the encrypted files.
Aside from data encryption and decryption, DarkSide ransomware also carries out data exfiltration and threatening victims that non-payment of ransom could lead to the public exposure of stolen data. In addition, the group behind DarkSide ransomware is also willing to carry out a Distributed Denial of Service (DDoS) attack against victims.
Tactics Used by DarkSide Ransomware Attackers
Researchers at FireEye in the blog post “Shining a Light on DARKSIDE Ransomware Operations” and researchers at McAfee in the blog post “DarkSide Ransomware Victims Sold Short” found that the group behind the DarkSide ransomware employed the following tactics:
. Password Spraying Attack Against Corporate VPN
To gain initial access to their victim’s network, the group behind DarkSide ransomware used password spraying against corporate VPN. In password spraying, an attacker circumvents the account lock-out countermeasures by trying the same password across many accounts before trying another password.
. Exploitation of CVE-2021-20016
To gain initial access to their victim’s network, the attackers exploited CVE-2021-20016, a SQL-Injection vulnerability in the SonicWall product that allows a remote unauthenticated attacker to perform SQL query to access username password and other session-related information.
. Phishing Emails
To gain initial access to their victim’s network, the attackers also used phishing emails to deliver the SMOKEDHAM – a malicious software (malware) that supports keylogging, taking screenshots and executing arbitrary .NET commands.
. Exploitation of Remote Desktop Protocol (RDP) Vulnerabilities
To gain initial access to their victim’s network, the attackers also exploited RDP, a proprietary protocol developed by Microsoft that allows users the ability to connect to another computer over the internet. In the past few years, a handful of security vulnerabilities on RDP had been identified and patched. Many, however, fail to apply the latest RDP patch.
. Leveraging TeamViewer
To establish persistence within the victim environment, the attackers also leveraged TeamViewer – a legitimate software that allows access to computers and networks remotely.
. Leveraging Mimikatz
To gain more privileges on the victim’s network, the attackers also used Mimikatz for credential harvesting.
. Leveraging NGROK
To bypass firewalls and expose remote desktop service ports, like RDP and WinRM, to the open internet, the attackers used the publicly available NGROK.
. Leveraging Cobalt Strike BEACON
To maintain a foothold on the victim’s network, the attackers used Cobalt Strike BEACON. Cobalt Strike is a commercially available penetration testing tool. The group behind Cobalt Strike describes BEACON as a tool to “egress a network over HTTP, HTTPS, or DNS.”
Cybersecurity Best Practices
Below are some of the cybersecurity best practices in order to reduce your organization’s vulnerability to ransomware such as DarkSide and reduce the risk of severe business degradation once impacted by ransomware:
Use multi-factor authentication as an added protection to the single-factor authentication: the traditional username and password combination.
Filter emails to prevent malicious executable files from reaching end users.
Filter network traffic to prevent inbound and outbound communications with known malicious IP addresses.
Keep all software up to date by applying the latest patches in a timely manner.
Protect RDP with strong passwords, multi-factor authentication, VPN other security protections.
Implement application allow listing, allowing the systems to execute only software programs that are known and permitted by the security policy.
It’s important to note that the tactics above-mentioned aren’t just used by the group behind DarkSide ransomware. The said tactics are widely used as well by ransomware groups and other malware operators. As such, the cybersecurity best practices above-mentioned also apply to other forms of attacks.
To date, the group behind the Darkside ransomware has gone dark, making it unclear whether the group has ceased, suspended operation, or has changed its operations or maneuvering an exit. Since March 13, all the dark websites used by the group behind Darkside are down. These sites were used by the group to communicate with the public.
Investigation Shows Ryuk Ransomware Attack Caused by Pirated Software, Lack of Network Protection
Sophos recently revealed that a cyberattack involving Ryuk ransomware targeting a European biomolecular research institute was caused by a pirated software and lack of network protection.
According to Sophos, its Rapid Response team was called in to respond to a Ryuk ransomware attack targeting a European biomolecular research institute – an organization that partners with local universities and works with students on various programs.
The Ryuk ransomware attack on the European biomolecular research institute, Sophos reported, costs the institute a week’s worth of vital research data, as even though the institute had backups, these backups weren’t up to date. The operation of the institute was also impacted since all computer and server files were required to be rebuilt before the data could be restored.
A review of logs and historical data available traced the initial compromise of the Ryuk ransomware attack on the European biomolecular research institute to the moment when one of the institute’s partners, an external university student, installed a pirated data visualization software on the said student’s laptop.
The investigating team found that the institute allowed people outside the organization to access its network, with partners such as university students allowed to access the institute’s network via remote Citrix sessions without the need for two-factor authentication using their own personal computers.
The investigating team found that the partner-student of the institute who installed the pirated software posted a question on an online research forum asking if anyone knew of a free alternative of the data visualization software, of which an original software costs hundreds of dollars a year. When the partner-student of the institute didn’t find a free version, a pirated version was used instead.
According to Sophos’ Rapid Response team, the pirated software was a pure malicious software (malware) that immediately triggered a security alert from Windows Defender. In order to install the pirated software, the partner-student of the institute disabled Windows Defender as well disabled Windows Security Firewall.
The installed pirated software-malware capabilities include logging keystrokes, stealing browser, cookies and clipboard data. The pirated software-malware also enabled the attackers to steal the student’s access credentials for the institute’s network.
According to Sophos’ Rapid Response team, 13 days after the installation of the pirated software-malware, a remote desktop protocol (RDP) connection was registered on the institute’s network using the student’s credentials, and 10 days after this connection was made the Ryuk ransomware was launched. The investigating team added that the institute’s RDP connection triggers the automatic installation of a printer driver, enabling users to print documents remotely.
“It is unlikely that the operators behind the ‘pirated software’ malware are the same as the ones who launched the Ryuk attack,” said Peter Mackenzie, manager of Rapid Response at Sophos. “The underground market for previously compromised networks offering attackers easy initial access is thriving, so we believe that the malware operators sold their access on to another attacker. The RDP connection could have been the access brokers testing their access.”
Cybersecurity Best Practices
The Ryuk ransomware attack that targeted the European biomolecular research institute is a hard-earned lesson for the community.
While the partner-student of the institute is clearly at fault for using pirated software, the said cyberattack exposed the institute’s network weaknesses. Here are some of the cybersecurity best practices in order to fortify your organization’s network against cyberattacks such as Ryuk ransomware attack:
RDP is a proprietary protocol developed by Microsoft that allows users the ability to connect to another computer over the internet. In the blog post "Cybercriminals Actively Exploiting RDP to Target Remote Organizations", McAfee Labs said that as a result of the COVID-19 restrictions, organizations wanting to maintain operational continuity have allowed their employees to access networks remotely via RDP with minimal security checks in place, giving cyber attackers easy access to these networks.
In the past few years, a handful of RDP security vulnerabilities have been identified and patched by Microsoft. Organizations that lagged behind in applying these RDP patches are vulnerable to attacks.
In the blog post “Data science for cybersecurity: A probabilistic time series model for detecting RDP inbound brute force attacks,” Microsoft said that RDPs that are not protected by strong passwords, multi-factor authentication, virtual private networks (VPNs), and other security protections are vulnerable to brute force attack – a type of cyberattack that uses the trial-and-error method in guessing the correct username and password combination.
Unpatched VPN Vulnerabilities: Attackers’ New Gateway to Gain Access to Victims’ Networks
A new report showed that ransomware attackers are using unpatched VPN vulnerabilities to gain access to victims’ networks.
Fortinet VPN Vulnerabilities
In the report “Vulnerability in FortiGate VPN servers is exploited in Cring ransomware attacks,” researchers at Kaspersky Lab found that the group behind the ransomware called “Cring” gained access to victims’ networks by exploiting CVE-2018-13379 – a known security vulnerability in Fortinet FortiOS under SSL VPN web portal that allows an unauthenticated attacker to download system files via special crafted HTTP resource requests.
According to researchers at Kaspersky Lab, CVE-2018-13379 vulnerability was used to extract the session file of the VPN Gateway. The session file contains valuable information, such as the username and plaintext password, the researchers said.
Researchers at Kaspersky Lab added that several days prior to the start of the main attack phase, the attackers performed test connections to the VPN Gateway. The attackers may have identified the vulnerable device themselves by scanning IP addresses, the researchers said, alternatively, they may have bought a ready-made list containing IP addresses of vulnerable Fortinet VPN Gateway devices as an offer to buy a database of vulnerable Fortinet VPN Gateway devices appeared on a dark web forum in autumn of 2020.
In a joint advisory "APT Actors Exploit Vulnerabilities to Gain Initial Access for Future Attacks," the Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) reported that in March 2021 they observed threat actors scanning the internet for Fortinet VPN Gateway devices that didn’t apply the security patches to security vulnerabilities CVE-2018-13379, CVE-2020-12812, and CVE-2019-5591. Fortinet, for its part, had issued a security patch for each of the said three security vulnerabilities.
CVE-2020-12812 is a security vulnerability in Fortinet VPN devices that can allow threat actors to log in successfully without being prompted for the second factor of authentication if they changed the case of their username. CVE-2019-5591, meanwhile, is a security vulnerability in Fortinet VPN Gateway devices that can allow an unauthenticated attacker on the same subnet to intercept sensitive information by impersonating the LDAP server.
“The APT actors may be using any or all of these CVEs to gain access to networks across multiple critical infrastructure sectors to gain access to key networks as pre-positioning for follow-on data exfiltration or data encryption attacks,” FBI and CISA said.
Typical of ransomware, Cring encrypts victims’ files and demands from victims to pay a certain amount (payable in bitcoin) in exchange for the decryption keys that would unlock the encrypted files.
Swisscom’s CSIRT and Kaspersky Lab reported that in the case of Cring ransomware attacks, after the attackers gained access to victims’ networks, they dropped into the victims’ networks customized Mimikatz and followed by CobaltStrike. Mimikatz is an open-source software that allows users to view and save authentication credentials.
CobaltStrike, meanwhile, refers to commercial penetration testing toolkits usually used by security researchers. Malicious software (malware) developers, meanwhile, have cracked and abused CobaltStrike for malicious purposes.
According to researchers at Kaspersky Lab, after Cring ransomware attackers gained access into the victim’s network by exploiting CVE-2018-13379, the attackers then dropped Mimikatz into the compromised system. The researchers said Mimikatz was used to steal the account credentials of Windows users who had previously logged in to the compromised system. With the help of Mimikatz, the attackers were able to compromise the domain administrator account.
After compromising the domain administrator account, the researchers said, Cring ransomware attackers distributed malware to other systems on the organization’s network through the use of Cobalt Strike. The Cobalt Strike Beacon backdoor, researchers at Kaspersky Lab said, provided the attackers with remote control of the infected system.
Cybersecurity Best Practices
Here are some of the best practices in order to prevent Cring ransomware attacks and ransomware attacks in general:
Keep all software up to date
The group behind Cring ransomware exploited the fact that despite the availability of a security patch for CVE-2018-13379, many users have delayed the application of this security patch. If your organization has delayed the application of the security patch for CVE-2018-13379, assume that your organization’s network has already been compromised.
Implement the principle of least privilege
Change the active directory policy in line with the principle of least privilege – a security best practice that requires limiting privileges to the minimum necessary to perform a job. An active directory policy that’s in line with the principle of least privilege only allows users to log in only to those systems needed to perform a function.
Practice Network Segmentation
Network segmentation refers to the practice of subdividing your organization’s network into sub-networks so that in case one sub-network is compromised, the other sub-networks won’t be affected. Restrict VPN access between sub-networks.
What Is Cryptomining Attack and How to Prevent Such Attack
The price of Bitcoin, the recognized leader among thousands of cryptocurrencies, has skyrocketed from $100 in 2013 to nearly $60,000 in March 2021.
The dizzying rise, not just by Bitcoin but by other cryptocurrencies as well, gives rise to the cyberattack known as “cryptomining attack.”
What Is Cryptomining Attack?
In cryptomining, also known as cryptojacking, an attacker uses the computing power of others, without the knowledge and permission from the owners of the computing power.
Bitcoin and other cryptocurrencies are virtual currencies. They only exist online and they’ve no physical notes or coins.
If done with the knowledge and permission of the computing power owner, cryptomining is legal. It’s important to note, however, that some countries ban cryptomining and cryptocurrency in general.
Many cryptocurrencies use cryptomining – the use of the processing power of computers to solve complex mathematical problems and verify cryptocurrency transactions. Crypto miners, meanwhile, are rewarded a certain amount of cryptocurrency for the use of computing power.
Cryptomining can be done on physical computers and via cloud computing. With physical computers, cryptomining attacks can easily be detected through a noticeable slowdown in device performance, reduction in productivity of the device, and unexpected increases in electricity costs.
With cloud-based cryptomining attacks, threat actors can illicitly use cloud computing resources for a long time without detection. Typically, cloud-based cryptomining attacks are only discovered when the victim finds an inflated cloud usage bill.
Prevalence of Cryptomining Attacks
Cryptomining attacks have been around for years. The noticeable uptick of cryptomining attacks happened in 2017 when the Bitcoin price reached $20,000.
Internet Exposed Kubernetes Pods
In February 2018, researchers at RedLock reported that Tesla fell victim to cryptomining attack. “The hackers had infiltrated Tesla’s Kubernetes console which was not password protected,” RedLock researchers said. “Within one Kubernetes pod, access credentials were exposed to Tesla’s AWS environment which contained an Amazon S3 (Amazon Simple Storage Service) bucket that had sensitive data such as telemetry. In addition to the data exposure, hackers were performing crypto mining from within one of Tesla’s Kubernetes pods.”
The cryptocurrency that was mined using Tesla’s computing resources was Monero. To date, the price of Monero is $261.57.
QNAP NAS Vulnerabilities
Researchers at 360 Netlab reported that on March 2, 2021, they detected attacks targeting QNAP NAS devices via the unauthorized remote command execution vulnerabilities, specifically CVE-2020-2506 and CVE-2020-2507.
CVE-2020-2506 is a security vulnerability in the QNAP NAS device that allows attackers to compromise the device’s software security, allowing the attackers to gain privileges, or reading sensitive information. CVE-2020-2507, meanwhile, is a command injection vulnerability in the QNAP NAS device that can allow remote attackers to run arbitrary commands.
Successful exploitation of CVE-2020-2506 and CVE-2020-2507, researchers at 360 Netlab said, allowed the attacker to gain root privilege on the devices and perform cryptomining attacks. Researchers at 360 Netlab named the malicious software (malware) that exploits CVE-2020-2506 and CVE-2020-2507 in QNAP NAS devices and conduct cryptomining activities on these devices as “UnityMiner.”
UnityMiner, 360 Netlab researchers said, allows the attackers to hide the illicit cryptomining process and the real CPU memory resource usage information. With UnityMiner, the researchers said, QNAP users who check the system usage via the WEB management interface cannot see the abnormal system behavior.
In January 2021, Imperva researchers reported a botnet in which one of its primary activities was performing cryptomining attacks.
Botnet, also known as zombie army, is a group of hijacked internet-connected computers each injected with malware and controlled from a remote location by an attacker to perform malicious activities such as cryptomining. According to Imperva researchers, the malware that they discovered exploited the security vulnerability designated as CVE-2021-3007.
The CVE-2021-3007 vulnerability has two opposing claims: one claim is that this is a Zend Framework vulnerability that can lead to remote code execution; the other claim, meanwhile, is that this is a "vulnerability in the PHP language itself."
According to Imperva researchers, successful exploitation of CVE-2021-3007 allows the attackers to run XMRig – a legitimate open-source software that utilizes system CPUs to mine the cryptocurrency Monero. Cybercriminals, however, abuse XMRig to earn cryptomining revenue by launching cryptomining attacks on victims’ computing resources.
In the case of a botnet, once a victim’s computer is enslaved as one of the zombie armies and injected with malware and controlled from a remote location by an attacker to perform malicious activities, there’s no limit to what the attacker can do. In addition to illicit cryptomining, your organization’s computers could be used for other malicious activities such as distributed denial-of-service (DDoS) attacks.
Best Practices to Prevent Cryptomining Attacks
Here are some of the best practices in order to prevent threat actors from using your organization’s computing power for illicit cryptomining:
Sierra Wireless Becomes Latest Ransomware Attack Victim
Sierra Wireless, one of the world’s leading IoT solutions providers, recently announced it was a victim of a ransomware attack.
Last March 23rd, Sierra Wireless announced that it discovered on March 20, 2021, it was hit by a ransomware attack.
In a ransomware attack, computer files are encrypted, blocking a victim from accessing these files. A ransomware attacker then demands from the victim to pay a specified amount in exchange for the decryption key that would unlock the encrypted files.
In recent months, it has become a trend among ransomware attackers to demand from ransomware victims a second ransom demand in exchange for the non-publication of data stolen during the ransomware attack. In the case of the ransomware attack on Sierra Wireless, it wasn’t disclosed whether or not the attacker or attackers demanded the second ransom or whether or not the company paid ransom.
As a result of the ransomware attack, Sierra Wireless said it halted production at its manufacturing sites. The company added that its corporate website and other internal operations have also been disrupted by the ransomware attack.
As a result of the ransomware attack, Sierra Wireless said it was withdrawing its First Quarter 2021 guidance. In February 2021, the company released its 2020 full year revenue and First Quarter 2021 guidance.
Sierra Wireless reported that its total revenue reached $448.6 million in 2020. For the First Quarter of 2021, the company said it projected to earn $109.9 million. In its March 26th update about the ransomware attack, Sierra Wireless said it has resumed production and started to recover its internal systems.
“Sierra Wireless maintains a clear separation between its internal IT systems and its customer-facing products and services,” the company said. “Sierra Wireless believes that the impact of the attack was limited to Sierra Wireless’ internal systems and corporate website, and that its products and connectivity services were not impacted, and its customers’ products and systems were not breached during the attack.”
The company added that it doesn’t expect that there will be any product security patches, or firmware or software updates required as a result of the ransomware attack.
Prevalence of Ransomware Attacks
IBM reported that ransomware was the cause of nearly one in four real-life cyberattacks worldwide that the company responded to in 2020. IBM added that ransomware attacks in 2020 were “aggressively evolving to include double extortion tactics.”
According to IBM, the group behind the ransomware called “Sodinokibi” – the most commonly observed ransomware group in 2020 – earned over $123 million in 2020, with nearly two-thirds of its victims paying a ransom. IBM added that the group behind Sodinokibi stole from victims approximately 21.6 terabytes of data and approximately 43% of ransomware victims had their data leaked for the public to see.
IBM further reported that Sodinokibi and the other successful ransomware groups in 2020 were focused on stealing and publishing the data of victims who refused to pay ransom.
IBM added that the most successful ransomware groups in 2020 were focused on creating ransomware-as-a-service cartels. In ransomware-as-a-service, one group maintains the ransomware code and another group, known as affiliates, spread the ransomware. Affiliates are known to distribute ransomware in any way they like.
In the blog post “McAfee ATR Analyzes Sodinokibi aka REvil Ransomware-as-a-Service – What The Code Tells Us,” McAfee Labs reported that while Sodinokibi ransomware affiliates used different modus operandi, it did notice many started with a breach of Remote Desktop Protocol (RDP) – a proprietary protocol developed by Microsoft that allows Windows users to remotely connect to another Windows computer.
RDP servers that are exposed to the internet through the use of weak passwords and unprotected by multi-factor authentication (MFA), virtual private networks (VPNs), and other security protections, are of particular interest to cyberattackers. RDP is often breached via brute force attacks, in which the attacker submits many username and password combinations in the hope of guessing the correct combination.
“Through RDP brute force, threat actor groups can gain access to target machines and conduct many follow-on activities like ransomware and coin mining operations,” Microsoft Defender Security Research Team said in the blog post "Data science for cybersecurity: A probabilistic time series model for detecting RDP inbound brute force attacks."
Cybersecurity Best Practices Against Ransomware
Network segmentation is one of the cybersecurity best practices in protecting your organization’s network from ransomware. In network segmentation, your organization’s IT network is divided into sub-networks so that in case something bad happens to one sub-network, the other sub-networks won’t be affected. In the case of Sierra Wireless ransomware attack, the company said it maintains a clear separation between its internal IT systems and its customer-facing products and services.
It’s also important to backup your organization’s critical data regularly, following the 3-2-1 backup rule. In 3-2-1 backup rule, 3 copies of your organization’s critical data are kept, with copies stored on 2 different media, and one of these copies must be kept offsite for disaster recovery.
As mentioned, one of the favorite entry points of ransomware attackers into their victims’ networks is via RDP servers exposed to the internet. Protect RDP servers via strong passwords, MFA, VPN, and other security protections.
Is Network-Level Blocking the Right Solution to Limiting Botnet Traffic?
The Government of Canada, through the Canadian Radio-television and Telecommunications Commission, recently called on stakeholders to comment on its proposal to develop a network-level blocking framework that will limit the harm botnets cause to Canadians.
In the "Call for comments – Development of a network-level blocking framework to limit botnet traffic and strengthen Canadians’ online safety," the Commission said it’s the principal enforcement agency for the Personal Information Protection and Electronic Documents Act and the Telecommunications Act – Canada’s Anti-Spam Legislation, also known as CASL. “Botnet activity is by definition a CASL violation, as is the botnet itself,” the Commission said. “One way that TSPs [telecommunications service providers] can limit anti-CASL behaviour is by blocking botnet traffic.”
What Are Botnets?
Botnets are networks of hijacked computers that are infected by malicious software (malware). One way by which this malware arrives on the hijacked computer is through phishing – a type of cyberattack in which the attacker masquerades as a trusted entity and tricks an email receiver to click on a malicious attachment or link.
Clicking this malicious attachment or link could lead to the downloading and running of malware on the email recipient’s computer. Once the malware is inside the victim’s computer, it contacts the attacker’s command and control center, allowing the attacker to control the malware-infected computer and using it to commit cybercrimes such as further phishing campaigns, credential stuffing, ransomware, or distributed denial-of-service (DDoS).
According to Commission, botnets are the basis for an increasingly large proportion of cyber threats to individuals, corporations, and institutions in Canada.
In mid-March this year, Canada Revenue Agency (CRA) announced that it locked out 800,000 CRA user IDs and passwords as they may have been obtained by unauthorized third parties or have been identified as being available to unauthorized individuals.
CRA said, “We wish to reiterate that these user IDs and passwords were not compromised as a result of a breach of CRA’s online systems, rather they may have been obtained by unauthorized third parties and through a variety of means by sources external to the CRA, such as email phishing schemes or third party data breaches.”
In August 2020, the Government of Canada, through the Treasury Board of Canada Secretariat, reported that attackers fraudulently accessed nearly 5,500 CRA accounts. In a press conference in August 2020, Marc Brouillard, acting Chief Technology Officer for the Treasury Board of Canada Secretariat said that at one point, the CRA web portal was attacked by a large amount of traffic using a "botnet to attempt to attack the services through credential stuffing".
Credential stuffing, also known as account takeover, uses a large number of stolen username and password combinations from other websites and tests these stolen credentials to login to a target website. Credential stuffing are launched through botnets and across different IP addresses.
Network-Level Blocking Framework Proposal
The Commission proposes that telecommunications service providers can introduce network-level blocking using a variety of techniques such as domain-based blocking, Internet Protocol (IP)-based blocking, and protocol-based blocking.
“Internet users access websites by clicking on links or by entering domains (www.example.com) into a browser,” Commission said. “To access a webpage, the domain has to first be translated into the IP address of the server that hosts the webpage. This translation happens through the Domain Name System (DNS), which maps domain names to IP addresses. Once the IP address is found, the Internet user’s device can then route communication to the website’s server and download the webpage.”
In domain-based blocking when an infected device requests a blocklisted command and control domain, the DNS will either reply that the domain is unknown or will redirect the user to a site stating that the requested domain isn’t permitted.
In IP-based blocking, a firewall is used to prevent communication to the IP addresses of suspected command and control servers while letting other communication through. Protocol-based blocking, meanwhile, refers to a targeted form of IP-based blocking limited to a select group of services on a specified server.
In its reply to the network-level blocking framework proposal, the Royal Canadian Mounted Police (RCMP) said it supports the Commission’s proposal as “criminal botnet operations and infrastructure continues to underpin various cybercrime threats, such as ransomware, Distributed Denial of Service (DDoS) attacks, campaign-level phishing activities, among other cyber intrusions.”
RCMP said that in 2016, it took part in a global effort to dismantle the network called “Avalanche,” which included a botnet infrastructure that facilitated the widespread malware attacks targeting financial institutions and other sectors. RCMP said that the dismantlement of the Avalanche network, which spread across 30 countries, resulted in multiple arrests, seizures of command and control server infrastructure, and over 800,000 domains were seized, sinkholed, or blocked.
In response to the Commission’s proposal, Bell Canada said, “There is no one-size-fits-all detection and mitigation method.” It added that once the Commission approves one type of blocking “malicious actors can be expected to change their techniques and implement new botnet strategies to evade the regulated mandatory form of blocking.”
In response to the Commission’s proposal, Rogers Communications said, “Blocking of botnet traffic is a highly technical matter that requires in-depth security intelligence.” It added that the “proposal for a single network blocking framework is not the best approach to tackle cyber crime.”
Telus Communications, for its part, said, “The Commission’s proposal to focus on TSPs in an effort to limit botnets is a narrow approach that, absent other stakeholder action, will be ineffective.” It added that network-level blocking is a “reactive measure – it is not implemented until malicious traffic is detected from an already
Steve E. Driz, I.S.P., ITCP