US-CERT- AA20-239A: FASTCash 2.0: North Korea's BeagleBoyz Robbing Banks

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Netwörkheäd

October 24, 2020, 06:12:56 PM
AA20-239A: FASTCash 2.0: North Korea's BeagleBoyz Robbing Banks

[html]Original release date: August 26, 2020 | Last revised: October 24, 2020

Summary

This Alert uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework. See the https://attack.mitre.org/versions/v7/matrices/enterprise/">ATT&CK for Enterprise framework for all referenced threat actor techniques.



This joint advisory is the result of analytic efforts among the Cybersecurity and Infrastructure Security Agency (CISA), the Department of the Treasury (Treasury), the Federal Bureau of Investigation (FBI) and U.S. Cyber Command (USCYBERCOM). Working with U.S. government partners, CISA, Treasury, FBI, and USCYBERCOM identified malware and indicators of compromise (IOCs) used by the North Korean government in an automated teller machine (ATM) cash-out scheme—referred to by the U.S. Government as "FASTCash 2.0: North Korea's BeagleBoyz Robbing Banks."



CISA, Treasury, FBI, and USCYBERCOM highlight the cyber threat posed by North Korea—formally known as the Democratic People's Republic of Korea (DPRK)—and provide recommended steps to mitigate the threat.



Refer to the following Malware Analysis Reports for associated IOCs: https://us-cert.cisa.gov/ncas/analysis-reports/ar20-045c">CROWDEDFLOUNDER, https://us-cert.cisa.gov/ncas/analysis-reports/ar20-239a">ECCENTRICBANDWAGON, https://us-cert.cisa.gov/ncas/analysis-reports/ar19-252b">ELECTRICFISH, https://us-cert.cisa.gov/ncas/analysis-reports/ar20-239c">FASTCash for Windows, https://us-cert.cisa.gov/ncas/analysis-reports/ar20-045g">HOPLIGHT, and https://us-cert.gov/ncas/analysis-reports/ar20-239b">VIVACIOUSGIFT.



https://us-cert.cisa.gov/sites/default/files/publications/AA20-239A_FASTCash2.0_508.pdf">Click here for a PDF version of this report.



!!!WARNING!!!


Since February 2020, North Korea has resumed targeting banks in multiple countries to initiate fraudulent international money transfers and ATM cash outs. The recent resurgence follows a lull in bank targeting since late 2019. This advisory provides an overview of North Korea's extensive, global cyber-enabled bank robbery scheme, a short profile of the group responsible for this activity, in-depth technical analysis, and detection and mitigation recommendations to counter this ongoing threat to the Financial Services sector.


!!!WARNING!!!


 


Technical Details

North Korea's intelligence apparatus controls a hacking team dedicated to robbing banks through remote internet access. To differentiate methods from other North Korean malicious cyber activity, the U.S. Government refers to this team as BeagleBoyz, who represent a subset of HIDDEN COBRA activity. The BeagleBoyz overlap to varying degrees with groups tracked by the cybersecurity industry as Lazarus, Advanced Persistent Threat 38 (APT38), Bluenoroff, and Stardust Chollima and are responsible for the FASTCash ATM cash outs reported in October 2018, fraudulent abuse of compromised bank-operated SWIFT system endpoints since at least 2015, and lucrative cryptocurrency thefts. This illicit behavior has been identified by the United Nations (UN) DPRK Panel of Experts as evasion of UN Security Council resolutions, as it generates substantial revenue for North Korea. North Korea can use these funds for its UN-prohibited nuclear weapons and ballistic missile programs. Additionally, this activity poses significant operational risk to the Financial Services sector and erodes the integrity of the financial system.



The BeagleBoyz's bank robberies pose severe operational risk for individual firms beyond reputational harm and financial loss from theft and recovery costs. The BeagleBoyz have attempted to steal nearly $2 billion since at least 2015, according to public estimates. Equally concerning, these malicious actors have manipulated and, at times, rendered inoperable, critical computer systems at banks and other financial institutions.  




       
  • In 2018, a bank in Africa could not resume normal ATM or point of sale services for its customers for almost two months following an attempted FASTCash incident.

    •    
  • The BeagleBoyz often put destructive anti-forensic tools onto computer networks of victim institutions. Additionally, in 2018, they deployed wiper malware against a bank in Chile that crashed thousands of computers and servers to distract from efforts to send fraudulent messages from the bank's compromised SWIFT terminal.



North Korea's widespread international bank robbery scheme that exploits critical banking systems may erode confidence in those systems and presents risks to financial institutions across the world. Any BeagleBoyz robbery directed at one bank implicates many other financial services firms in both the theft and the flow of illicit funds back to North Korea. BeagleBoyz activity fits a known North Korean pattern of abusing the international financial system for profit.




       
  • Fraudulent ATM cash outs have affected upwards of 30 countries in a single incident. The conspirators have withdrawn cash from ATM machines operated by various unwitting banks in multiple countries, including in the United States.

    •    
  • The BeagleBoyz also use unwitting banks, including banks in the United States, for their SWIFT fraud scheme. These banks are custodians of accounts belonging to victim banks or unknowingly serve as a pass-through for the fraud. Most infamously, the BeagleBoyz stole $81 million from the Bank of Bangladesh in 2016. The Federal Reserve Bank of New York stopped the remainder of this attempted $1 billion theft after detecting anomalies in the transfer instructions they had received.




   
      
         
      
   

         

FASTCash Update



         

North Korea's BeagleBoyz are responsible for the sophisticated cyber-enabled ATM cash-out campaigns identified publicly as "FASTCash" in October 2018. Since 2016, the BeagleBoyz have perpetrated the FASTCash scheme, targeting banks' retail payment system infrastructure (i.e., switch application servers processing International Standards Organization [ISO] 8583 messages, which is the standard for financial transaction messaging).



         

Since the publication of the in October 2018, there have been two particularly significant developments in the campaign: (1) the capability to conduct the FASTCash scheme against banks hosting their switch applications on Windows servers, and (2) an expansion of the FASTCash campaign to target interbank payment processors.



         

                
  • In October 2018, the U.S. Government identified malware used in the FASTCash scheme that has the capability to manipulate AIX servers running a bank's switch application to intercept financial request messages and reply with fraudulent, but legitimate-looking, affirmative response messages to enable extensive ATM cash outs. The U.S. Government has since identified functionally equivalent malware for the Windows operating system. Please see the Technical Analysis section below for more information about the ISO 8583 malware for Windows.

    •             
  • The BeagleBoyz initially targeted switch applications at individual banks with FASTCash malware but, more recently, have targeted at least two regional interbank payment processors. This suggests the BeagleBoyz are exploring upstream opportunities in the payments ecosystem.

    •          


         

For more information about FASTCash, please see https://www.us-cert.gov/ncas/alerts/ta18-275a">https://www.us-cert.gov/ncas/alerts/TA18-275A.


         


BEAGLEBOYZ Profile



The BeagleBoyz, an element of the North Korean government's Reconnaissance General Bureau, have likely been active since at least 2014. As opposed to typical cybercrime, the group likely conducts well-planned, disciplined, and methodical cyber operations more akin to careful espionage activities. Their malicious cyber operations have netted hundreds of millions of U.S. dollars and are likely a major source of funding for the North Korean regime. The group has always used a calculated approach, which allows them to sharpen their tactics, techniques, and procedures while evading detection. Over time, their operations have become increasingly complex and destructive. The tools and implants employed by this group are consistently complex and demonstrate a strong focus on effectiveness and operational security.



Community Identifiers



The BeagleBoyz overlap to varying degrees with groups tracked by the cybersecurity industry as: APT38 (FireEye), Bluenoroff (Kaspersky), Lazarus Group (ESTSecurity), and Stardust Chollima (CrowdStrike).



Targeted Nations



The BeagleBoyz likely have targeted financial institutions in the following nations from 2015 through 2020: Argentina, Brazil, Bangladesh, Bosnia and Herzegovina, Bulgaria, Chile, Costa Rica, Ecuador, Ghana, India, Indonesia, Japan, Jordan, Kenya, Kuwait, Malaysia, Malta, Mexico, Mozambique, Nepal, Nicaragua, Nigeria, Pakistan, Panama, Peru, Philippines, Singapore, South Africa, South Korea, Spain, Taiwan, Tanzania, Togo, Turkey, Uganda, Uruguay, Vietnam, Zambia (figure 1).



https://us-cert.cisa.gov/sites/default/files/images/AA20-239A-image1.png" width="742" />



Figure 1: Nations probably targeted by BeagleBoyz since 2015



Anatomy of a BeagleBoyz Bank Heist



Figure 2 provides a graphical depiction of a BeagleBoyz bank heist. The next section describes in detail the end-to-end actions the BeagleBoyz take to rob financial institutions with a malicious cyber operation.



https://us-cert.cisa.gov/sites/default/files/images/AA20-239A-image2.png" width="553" />



Figure 2: BeagleBoyz Bank Heist overview



Technical Analysis



The BeagleBoyz use a variety of tools and techniques to gain access to a financial institution's network, learn the topology to discover key systems, and monetize their access. The technical analysis below represents an amalgamation of multiple known incidents, rather than details of a single operation. These findings are presented to highlight the group's ability to tailor their techniques to different targets and to adapt their methods over time. Consequently, there is a need for layered mitigations to effectively defend against this activity, as relying solely on network signature detection will not sufficiently protect against North Korea's BeagleBoyz.



Initial Access



The BeagleBoyz have used a variety of techniques, such as spearphishing and watering holes, to enable initial access into targeted financial institutions. Towards the end of 2018 through 2019 and in early 2020, the BeagleBoyz demonstrated the use of social engineering tactics by carrying out job-application themed phishing attacks using the following publicly available malicious files.



MD5: b484b0dff093f358897486b58266d069




MD5: f34b72471a205c4eee5221ab9a349c55




MD5: 4c26b2d0e5cd3bfe0a3d07c4b85909a4




MD5: 52ec074d8cb8243976963674dd40ffe7




MD5: d1d779314250fab284fd348888c2f955




MD5: cf733e719e9677ebfbc84a3ab08dd0dc




MD5: 01d397df2a1cf1d4c8e3615b7064856c


The BeagleBoyz may also be working with or contracting out to criminal hacking groups, like TA505, for initial access development. The third party typically uses commodity malware to establish initial access on a victim's network and then turns over the access to the BeagleBoyz for follow-on exploitation, which may not occur until months later.



The BeagleBoyz have also used the following techniques to gain an initial foothold on a targeted computer network (Initial Access [https://attack.mitre.org/versions/v7/tactics/TA0001/">TA0001]).





Execution



The BeagleBoyz selectively exploit victim computer systems after initially compromising a computer connected to a financial institution's corporate network. After gaining initial access to a financial institution's corporate network, the BeagleBoyz are selective in which victim systems they further exploit. The BeagleBoyz use a variety of techniques to run their code on local and remote victim systems [Execution [https://attack.mitre.org/versions/v7/tactics/TA0002/">TA0002]).





Persistence



The BeagleBoyz use many techniques to maintain access on compromised networks through system restarts, changed credentials, and other interruptions that could affect their access (Persistence [https://attack.mitre.org/versions/v7/tactics/TA0003/">TA0003]).




       
  • Add an entry to the "run keys" in the Registry or an executable to the startup folder to execute malware as the user logs in under the context of the user's associated permissions levels (Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder [https://attack.mitre.org/versions/v7/techniques/T1547/001/">T1547.001])

    •    
  • Install a new service that can be configured to execute at startup using utilities to interact with services or by directly modifying the Registry (Create or Modify System Process: Windows Service [https://attack.mitre.org/versions/v7/techniques/T1543/003/">T1543.003])

    •    
  • Compromise an openly accessible web server with a web script (known as web shell) to use the web server as a gateway into a network and to serve as redundant access or persistence mechanism (Server Software Component: Web Shell [https://attack.mitre.org/versions/v7/techniques/T1505/003/">T1505.003])

    •    
  • Manipulate accounts (e.g., modifying permissions, modifying credentials, adding or changing permission groups, modifying account settings, or modifying how authentication is performed) to maintain access to credentials and certain permission levels within an environment (Account Manipulation [https://attack.mitre.org/versions/v7/techniques/T1098/">T1098])

    •    
  • Steal the credentials of a specific user or service account to bypass access controls and retain access to remote systems and externally available services (Valid Accounts [https://attack.mitre.org/versions/v7/techniques/T1078/">T1078])

    •    
  • Use the Task Scheduler to run programs at system startup or on a scheduled basis for persistence, conduct remote execution for lateral movement, gain SYSTEM privileges for privilege escalation, or run a process under the context of a specified account (Scheduled Task/Job [https://attack.mitre.org/versions/v7/techniques/T1053/">T1053])

    •    
  • Abuse the Windows DLLs search order and programs that ambiguously specify DLLs to gain privilege escalation and persistence (Hijack Execution Flow: DLL Search Order Hijacking [https://attack.mitre.org/versions/v7/techniques/T1056/004/">T1056.004])

    •    
  • Exploit hooking to load and execute malicious code within the context of another process to mask the execution, allow access to the process's memory, and, possibly, gain elevated privileges (Input Capture: Credential API Hooking [https://attack.mitre.org/versions/v7/techniques/T1574/001/">T1574.001])

    •    
  • Use remote services to persist within a victim's network (External Remote Services [https://attack.mitre.org/versions/v7/techniques/T1133/">T1133])



Privilege Escalation



The BeagleBoyz often seek access to financial institutions' systems that have tiered user and system accounts with customized privileges. The BeagleBoyz must overcome these restrictions to access necessary systems, monitor normal user behavior, and install and execute additional malicious tools. To do so, the BeagleBoyz have used the following techniques to gain higher-level permissions on a system or network (Privilege Escalation [https://attack.mitre.org/versions/v7/tactics/TA0004/">TA0004]).





Defense Evasion



Throughout their exploitation of a financial institution's computer network, the BeagleBoyz have used different techniques to avoid detection by OS security features, system and network security software, and system audits (Defense Evasion [https://attack.mitre.org/versions/v7/tactics/TA0005/">TA0005]).





Credential Access



The BeagleBoyz may use malware like ECCENTRICBANDWAGON to log key strokes and take screen captures. The U.S. Government has identified some ECCENTRICBANDWAGON samples that have the ability to RC4 encrypt logged data, but the tool has no network functionality. The implant uses specific formatting for logged data and saves the file locally; another tool obtains the logged data. The implant also contains no mechanism for persistence or self-loading and expects a specific configuration file to be present on the system. A full technical report for ECCENTRICBANDWAGON is available at https://us-cert.cisa.gov/northkorea">https://us-cert.cisa.gov/northkorea.



The BeagleBoyz may not always need to use custom keyloggers like ECCENTRICBANDWAGON or other tools to obtain credentials from a compromised system. Depending on the victim's environment, the BeagleBoyz have used the following techniques to steal credentials (Credential Access [https://attack.mitre.org/versions/v7/tactics/TA0006/">TA0006]).





Discovery



Once inside a financial institution's network, the BeagleBoyz appear to seek two specific systems—the SWIFT terminal and the server hosting the institution's payment switch application. As they progress through a network, they learn about the systems they have accessed in order to map the network and gain access to the two goal systems. To do so, the BeagleBoyz have used the following techniques to gain knowledge about the systems and internal network (Discovery [https://attack.mitre.org/versions/v7/tactics/TA0007/">TA0007]).





Lateral Movement



To access a compromised financial institution's SWIFT terminal and the server hosting the institution's payment switch application, the BeagleBoyz leverage harvested credentials and take advantage of the accessibility of these critical systems from other systems in the institution's corporate network. Specifically, the BeagleBoyz have been known to create firewall exemptions on specific ports, including ports 443, 6443, 8443, and 9443. Depending on the configuration of compromised systems and the security environment of the victim's computer network, the BeagleBoyz have used the following techniques to enter and control remote systems on a compromised network (Lateral Movement [https://attack.mitre.org/versions/v7/tactics/TA0008/">TA0008]).





Collection



Depending on various environmental attributes the BeagleBoyz encounter during their exploitation, they may deploy a variety of reconnaissance tools or use commonly available administrative tools for malicious purposes.



The BeagleBoyz, like other sophisticated cyber actors, also appear to use resident, legitimate administrative tools for reconnaissance purposes when they are available; this is commonly known as "living off the land." PowerShell appears to be a popular otherwise-legitimate tool the BeagleBoyz favor for reconnaissance activities. For example, the BeagleBoyz often use publicly available code from PowerShell Empire for malicious purposes.



The BeagleBoyz have used the following techniques to gather information from exploited systems (Collection [https://attack.mitre.org/versions/v7/tactics/TA0009/">TA0009]).





Command and Control



The BeagleBoyz likely change tools—such as CROWDEDFLOUNDER and HOPLIGHT—over time to maintain remote access to financial institution networks and to interact with those systems.



Analysis of the following CROWDEDFLOUNDER samples was first released in October 2018 as part of the FASTCash campaign.



MD5 hash: 5cfa1c2cb430bec721063e3e2d144feb

MD5 hash: 4f67f3e4a7509af1b2b1c6180a03b3e4



The BeagleBoyz have used CROWDEDFLOUNDER as a remote access trojan (RAT) since at least 2018. The implant is designed to operate on Microsoft Windows hosts and can upload and download files, launch a remote command shell, inject into victim processes, obtain user and host information, and securely delete files. The implant may be packed with Themida to degrade or prevent effective reverse engineering or evade detection on a Windows host. It can be set to act in beacon or listening modes, depending on command line arguments or configuration specifications. The implant obfuscates network communications using a simple encoding algorithm. The listening mode of CROWDEDFLOUNDER facilitates proxies like ELECTRICFISH (discussed below) with tunneling traffic in a victim's network.



More recently, the U.S. Government has found HOPLIGHT malware on victim systems, suggesting the BeagleBoyz are using HOPLIGHT for similar purposes. HOPLIGHT has the same basic RAT functionality as the CROWDEDFLOUNDER implant. In addition, HOPLIGHT has the capability to create fraudulent Transport Layer Security (TLS) sessions to obfuscate command and control (C2) connections, making detection and tracking of the malware's communications difficult.



Full technical reports for CROWDEDFLOUNDER and HOPLIGHT are available at https://us-cert.cisa.gov/northkorea">https://us-cert.cisa.gov/northkorea.



The BeagleBoyz use network proxy tunneling tools—including VIVACIOUSGIFT and ELECTRICFISH—to tunnel communications from non-internet facing systems like an ATM switch application server or a SWIFT terminal to internet-facing systems. The BeagleBoyz use these network proxy tunneling tools, likely placed at or near a victim's network boundary, to tunnel other protocols such as RDP and Secure Shell or other implant traffic out from the internal network.



It appears that as the BeagleBoyz change proxy tools, there is some overlap between their use of older and newer malware. For example, the BeagleBoyz appear to have begun using ELECTRICFISH as they wound down use of VIVACIOUSGIFT. There has been a noticeable decline in ELECTRICFISH use following the U.S. Government's disclosure of it in May 2019.



Full technical reports for VIVACIOUSGIFT and ELECTRICFISH are available at https://us-cert.cisa.gov/northkorea">https://us-cert.cisa.gov/northkorea.



In addition to these tools, the BeagleBoyz have used the following techniques to communicate with financial institution victim systems under their control (Command and Control [https://attack.mitre.org/versions/v7/tactics/TA0011/">TA0011]).






   
      
         
      
   

         

Cryptocurrency Exchange Heists



         

In addition to robbing traditional financial institutions, the BeagleBoyz target cryptocurrency exchanges to steal large amounts of cryptocurrency, sometimes valued at hundreds of millions of dollars per incident. Cryptocurrency offers the BeagleBoyz an irreversible method of theft that can be converted into fiat currency because the permanent nature of cryptocurrency transfers do not allow for claw-back mechanisms. Working with U.S. Government partners, CISA, Treasury, FBI, and USCYBERCOM identified COPPERHEDGE as the tool of choice for the BeagleBoyz to exploit cryptocurrency exchanges. COPPERHEDGE is a full-featured remote access tool capable of running arbitrary commands, performing system reconnaissance, and exfiltrating data. Full technical analysis of COPPERHEDGE is available at https://us-cert.cisa.gov/northkorea">https://us-cert.cisa.gov/northkorea.


         


Exfiltration



During a cyber operation, the BeagleBoyz need to exfiltrate a variety of data from compromised systems. In addition to the C2 tools noted that have built-in exfiltration features, such as CROWDEDFLOUNDER and HOPLIGHT, the BeagleBoyz use the following techniques to steal data from a network (Exfiltration [https://attack.mitre.org/versions/v7/tactics/TA0010/">TA0010]).





Impact



The U.S. Government has observed the BeagleBoyz successfully monetize illicit access to financial institutions' SWIFT terminals to enable wire fraud and gain access to the institutions' payment switch application servers, which allowed fraudulent ATM cash outs. After gaining access to either one or both of these operationally critical systems, the BeagleBoyz monitor the systems to learn about their configurations and legitimate use patterns, and then they deploy bespoke tools to facilitate illicit monetization.



The cybersecurity community and Financial Services sector have released substantial information on the BeagleBoyz manipulation of compromised SWIFT terminals, describing their ability to monitor these systems, send fraudulent messages, and attempt to hide the fraudulent activity from detection. The discussion below focuses on the custom tools used to manipulate payment switch applications for ATM cash outs.



The BeagleBoyz use FASTCash malware to intercept financial request messages and reply with fraudulent but legitimate-looking affirmative response messages in the ISO 8583 format. The BeagleBoyz have functionally equivalent FASTCash malware for both UNIX and Windows that they deploy depending on the operating system running on the server hosting the bank's payment switch application.



FASTCash for UNIX is composed of AIX executable files designed to inject code and libraries into a currently running process. One AIX executable provides export functions, which allows an application to manipulate transactions on financial systems using the ISO 8583 international standard for financial transaction card-originated interchange messaging. The injected executables interpret financial request messages and construct fraudulent financial response messages. For more details on FASTCash for UNIX malware, please see the FASTCash report at https://www.us-cert.gov/ncas/alerts/TA18-275A">https://www.us-cert.gov/ncas/alerts/TA18-275A.



The BeagleBoyz use FASTCash for Windows to manipulate transactions processed by a switch application running on a Windows box. FASTCash for Windows is also specific to the ISO 8583 message format. The BeagleBoyz appear to have modified publicly available source code to write parts of the tool, likely to speed development. The malware contains code probably taken from open-source repositories on the internet to create hashmaps and hook functions and to parse ISO 8583 messages.



FASTCash for Windows injects itself into software running on a Windows platform. The malware then takes control of the software's network send and receive functions, allowing it to manipulate ISO 8583 messages. The U.S. Government has identified two variants of FASTCash for Windows. One variant supports ASCII encoding. The BeagleBoyz appear to have modified the second variant's message parsing code to support Extended Binary Coded Decimal Interchange Code (EBCIDC) encoding. Both ASCII and EBCDIC are character encoding formats.  



FASTCash for Windows malware uses code from github.com/petewarden/c_hashmap for hashmaps, code from Microsoft's Detours Library at github.com/Microsoft/Detours for hooking, and code from to parse ISO 8583 messages.



The malware hooks onto the send and receive function of the switch application so that it can process inbound request messages as they are received. FASTCash for Windows inspects the inbound message, probably looking for specific account numbers. If the account number matches an expected number, the malware constructs a fraudulent response message. If the account number does not match an expected number, the malware allows the request to pass through normally. If the malware constructs a fraudulent response message, it then sends it back to the acquirer without any further processing by the switch application, leaving the issuer without any awareness of the fraudulent transaction.



Full technical reports for FASTCash and FASTCash for Windows malware are available at https://us-cert.cisa.gov/northkorea">https://us-cert.cisa.gov/northkorea.



The BeagleBoyz have used the following techniques to manipulate business and operational processes for monetary or destructive purposes (Impact [https://attack.mitre.org/versions/v7/tactics/TA0040/">TA0040]).




Mitigations


       
  • Contact law enforcement, CISA, or Treasury immediately regarding any identified activity related to BeagleBoyz. (Refer to the Contact Information section.)

    •    
  • Incorporate IOCs identified in CISA's Malware Analysis Reports on https://us-cert.cisa.gov/northkorea">https://us-cert.cisa.gov/northkorea into intrusion detection systems and security alert systems to enable active blocking or reporting of suspected malicious activity.



Recommendations for all Financial Institutions





Recommendations for Institutions with Retail Payment Systems



Require chip and personal identification number (PIN) cryptogram validation.




       
  • Implement chip and PIN requirements for debit cards.

    •    
  • Validate card-generated authorization request cryptograms.

    •    
  • Use issuer-generated authorization response cryptograms for response messages.

    •    
  • Require card-generated authorization response cryptogram validation to verify legitimate response messages.



Isolate payment system infrastructure.




       
  • Require multi-factor authentication for any user to access the switch application server.

    •    
  • Confirm perimeter security controls prevent internet hosts from accessing the private network infrastructure servicing your payment switch application server.

    •    
  • Confirm perimeter security controls prevent all hosts outside of authorized endpoints from accessing your system, especially if your payment switch application server is internet accessible.



Logically segregate your operating environment.




       
  • Use firewalls to divide your operating environment into enclaves.

    •    
  • Use access control lists to permit/deny specific traffic from flowing between those enclaves.

    •    
  • Give special considerations to segregating enclaves holding sensitive information (e.g., card management systems) from enclaves requiring internet connectivity (e.g., email).



Encrypt data in transit.




       
  • Secure all links to payment system engines with a certificate-based mechanism, such as Mutual Transport Layer Security, for all external and internal traffic external.

    •    
  • Limit the number of certificates that can be used on the production server and restrict access to those certificates.



Monitor for anomalous behavior as part of layered security.




       
  • Configure the switch application server to log transactions and routinely audit transaction and system logs.

    •    
  • Develop a baseline of expected software, users, and logons and monitor switch application servers for unusual software installations, updates, account changes, or other activities outside of expected behavior.

    •    
  • Develop a baseline of expected transaction participants, amounts, frequency, and timing. Monitor and flag anomalous transactions for suspected fraudulent activity.



Recommendations for Organizations with ATM or Point of Sale Devices



Validate issuer responses to financial request messages.




       
  • Implement chip and PIN requirements for debit cards.

    •    
  • Require and verify message authentication codes on issuer financial request response messages.

    •    
  • Perform authorization response cryptogram validation for chip and PIN transactions.



Recommendations for All Organizations



Users and administrators should use the following best practices to strengthen the security posture of their organization's systems:




       
  • Maintain up-to-date antivirus signatures and engines.

    •    
  • Keep operating system patches up to date.

    •    
  • Disable file and printer sharing services. If these services are required, use strong passwords or Active Directory authentication.

    •    
  • Restrict users' ability (permissions) to install and run unwanted software applications. Do not add users to the local administrators' group unless required.

    •    
  • Enforce a strong password policy and require regular password changes.

    •    
  • Exercise caution when opening email attachments even if the attachment is expected and the sender appears to be known.

    •    
  • Enable a personal firewall on agency workstations and configure it to deny unsolicited connection requests.

    •    
  • Disable unnecessary services on agency workstations and servers.

    •    
  • Scan for and remove suspicious email attachments; ensure the scanned attachment is its "true file type" (i.e., the extension matches the file header).

    •    
  • Monitor users' web browsing habits; restrict access to sites with unfavorable content.

    •    
  • Exercise caution when using removable media (e.g., USB thumb drives, external drives, CDs).

    •    
  • Scan all software downloaded from the internet before executing.

    •    
  • Maintain situational awareness of the latest threats.

    •    
  • Implement appropriate access control lists.



Additional information on malware incident prevention and handling can be found in National Institute of Standards and Technology Special Publication 800-83, https://www.nist.gov/publications/guide-malware-incident-prevention-and-handling-desktops-and-laptops">Guide to Malware Incident Prevention and Handling for Desktops and Laptops.



 


Contact Information

Recipients of this report are encouraged to contribute any additional information that they may have related to this threat.



For any questions related to this report or to report an intrusion and request resources for incident response or technical assistance, please contact:





DISCLAIMER


 


This information is provided "as is" for informational purposes only. The United States Government does not provide any warranties of any kind regarding this information. In no event shall the United States Government or its contractors or subcontractors be liable for any damages, including but not limited to, direct, indirect, special or consequential damages, arising out of, resulting from, or in any way connected with this information, whether or not based upon warranty, contract, tort, or otherwise, whether or not arising out of negligence, and whether or not injury was sustained from, or arose out of the results of, or reliance upon the information.

 


The United States Government does not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply their endorsement, recommendation, or favoring by the United States Government.


 




           

Revisions


      
                        
  • August 26, 2020: Initial Version
    •                     
  • September 3, 2020: Updated PDF template
    •                     
  • October 10, 2020: Updated Initial Access section
    •       

      

           

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