US CERT: Technical Security Alerts
AA20-020A: Critical Vulnerability in Citrix Application Delivery Controller, Gateway, and SD-WAN WANOP
New vulnerabilities are continually emerging, but the best defense against attackers exploiting patched vulnerabilities is simple: keep software up to date. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats.
On January 14, 2020, Microsoft released software fixes to address 49 vulnerabilities as part of their monthly Patch Tuesday announcement. Among the vulnerabilities patched were critical weaknesses in Windows CryptoAPI and Windows Remote Desktop Protocol (RDP) server and client. An attacker could remotely exploit these vulnerabilities to decrypt, modify, or inject data on user connections:
- CryptoAPI spoofing vulnerability – CVE-2020-0601: This vulnerability affects all machines running 32- or 64-bit Windows 10 operating systems, including Windows Server versions 2016 and 2019. This vulnerability allows Elliptic Curve Cryptography (ECC) certificate validation to bypass the trust store, enabling unwanted or malicious software to masquerade as authentically signed by a trusted or trustworthy organization. This could deceive users or thwart malware detection methods such as antivirus. Additionally, a maliciously crafted certificate could be issued for a hostname that did not authorize it, and a browser that relies on Windows CryptoAPI would not issue a warning, allowing an attacker to decrypt, modify, or inject data on user connections without detection.
- Multiple Windows RDP vulnerabilities – CVE-2020-0609, CVE-2020-0610, and CVE-2020-0611: These vulnerabilities affect Windows Server 2012 and newer. In addition, CVE-2020-0611 affects Windows 7 and newer. These vulnerabilities—in the Windows Remote Desktop client and RDP Gateway Server—allow for remote code execution, where arbitrary code could be run freely. The server vulnerabilities do not require authentication or user interaction and can be exploited by a specially crafted request. The client vulnerability can be exploited by convincing a user to connect to a malicious server.
The Cybersecurity and Infrastructure Security Agency (CISA) is unaware of active exploitation of these vulnerabilities. However, because patches have been publicly released, the underlying vulnerabilities can be reverse-engineered to create exploits that target unpatched systems.
CISA strongly recommends organizations install these critical patches as soon as possible—prioritize patching by starting with mission critical systems, internet-facing systems, and networked servers. Organizations should then prioritize patching other affected information technology/operational technology (IT/OT) assets.Technical DetailsCryptoAPI Spoofing Vulnerability – CVE-2020-0601
A spoofing vulnerability exists in the way Windows CryptoAPI (Crypt32.dll) validates ECC certificates.
According to Microsoft, “an attacker could exploit the vulnerability by using a spoofed code-signing certificate to sign a malicious executable, making it appear the file was from a trusted, legitimate source. The user would have no way of knowing the file was malicious, because the digital signature would appear to be from a trusted provider.” Additionally, “a successful exploit could also allow the attacker to conduct man-in-the-middle attacks and decrypt confidential information on user connections to the affected software.”
A cyber attacker could exploit CVE-2020-0601 to obtain sensitive information, such as financial information, or run malware on a targeted system; for example:
- A maliciously crafted certificate could appear to be issued for a hostname that did not authorize it, preventing a browser that relies on Windows CryptoAPI from validating its authenticity and issuing warnings. If the certificate impersonates a user’s bank website, their financial information could be exposed.
- Signed malware can bypass protections (e.g., antivirus) that only run applications with valid signatures. Malicious files, emails, and executables can appear legitimate to unpatched users.
The Microsoft Security Advisory for CVE-2020-0601 addresses this vulnerability by ensuring that Windows CryptoAPI completely validates ECC certificates.Detection Measures
The National Security Agency (NSA) provides detection measures for CVE-2020-0601 in their Cybersecurity Advisory: Patch Critical Cryptographic Vulnerability in Microsoft Windows Clients and Servers.Windows Remote Desktop Server Vulnerabilities – CVE-2020-0609/CVE-2020-0610
According to Microsoft, “A remote code execution vulnerability exists in Windows Remote Desktop Gateway (RD Gateway) when an unauthenticated attacker connects to the target system using RDP and sends specially crafted requests. This vulnerability is pre-authentication and requires no user interaction.”,
- Affects all supported Windows Server versions (Server 2012 and newer; support for Server 2008 ends January 14, 2020);
- Occurs pre-authentication; and
- Requires no user interaction to perform.
According to Microsoft, “A remote code execution vulnerability exists in the Windows Remote Desktop Client when a user connects to a malicious server. An attacker who successfully exploited this vulnerability could execute arbitrary code on the computer of the connecting client.”
CVE-2020-0611 requires the user to connect to a malicious server via social engineering, Domain Name Server (DNS) poisoning, a man-in the-middle attack, or by the attacker compromising a legitimate server.
The Microsoft Security Advisory for CVE-2020-0611 addresses this vulnerability.Impact
A successful network intrusion can have severe impacts, particularly if the compromise becomes public and sensitive information is exposed. Possible impacts include:
- Temporary or permanent loss of sensitive or proprietary information,
- Disruption to regular operations,
- Financial losses relating to restoring systems and files, and
- Potential harm to an organization’s reputation.
CISA strongly recommends organizations read the Microsoft January 2020 Release Notes page for more information and apply critical patches as soon as possible—prioritize patching by starting with mission critical systems, internet-facing systems, and networked servers. Organizations should then prioritize patching other affected IT/OT assets.
- Review Guide to Enterprise Patch Management Technologies, NIST Special Publication 800-40 Revision 3. Patch management is the process for identifying, acquiring, installing, and verifying patches for products and systems. This publication is designed to assist organizations in understanding the basics of enterprise patch management technologies. It explains the importance of patch management and examines the challenges inherent in performing patch management. It provides an overview of enterprise patch management technologies, and also briefly discusses metrics for measuring the technologies’ effectiveness.
- Review CISA Insights publications. Informed by U.S. cyber intelligence and real-world events, each CISA Insight provides background information on particular cyber threats and the vulnerabilities they exploit, as well as a ready-made set of mitigation activities that non-federal partners can implement. Printable materials can be found by visiting: https://www.cisa.gov/publication/cisa-insights-publications.
- Review CISA’s Cyber Essentials. CISA’s Cyber Essentials is a guide for leaders of small businesses as well as leaders of small and local government agencies to develop an actionable understanding of where to start implementing organizational cybersecurity practices. Essentials are the starting point to cyber readiness. To download the guide, visit: https://www.cisa.gov/publication/cisa-cyber-essentials.
-  Microsoft Security Advisory for CVE-2020-0601
-  NSA Cybersecurity Advisory: Patch Critical Cryptographic Vulnerability in Microsoft Windows Clients and Servers
-  Microsoft Security Advisory for CVE-2020-0609
-  Microsoft Security Advisory for CVE-2020-0610
-  Microsoft Security Advisory for CVE-2020-0611
-  CISA Blog: Windows Vulnerabilities that Require Immediate Attention
-  CERT/CC Vulnerability Note VU#849224
-  CERT/CC Vulnerability Note VU#491944
- January 14, 2020: Initial version
Unpatched Pulse Secure VPN servers continue to be an attractive target for malicious actors. Affected organizations that have not applied the software patch to fix a remote code execution (RCE) vulnerability, known as CVE-2019-11510, can become compromised in an attack. 
Although Pulse Secure  disclosed the vulnerability and provided software patches for the various affected products in April 2019, the Cybersecurity and Infrastructure Security Agency (CISA) continues to observe wide exploitation of CVE-2019-11510.   
CISA expects to see continued attacks exploiting unpatched Pulse Secure VPN environments and strongly urges users and administrators to upgrade to the corresponding fixes. Timelines of Specific Events
- April 24, 2019 – Pulse Secure releases initial advisory and software updates addressing multiple vulnerabilities.
- May 28, 2019 – Large commercial vendors get reports of vulnerable VPN through HackerOne.
- July 31, 2019 – Full RCE use of exploit demonstrated using the admin session hash to get complete shell.
- August 8, 2019 – Meh Chang and Orange Tsai demonstrate the VPN issues across multiple vendors (Pulse Secure) with detailed attack on active VPN exploitation.
- August 24, 2019 – Bad Packets identifies over 14,500 vulnerable VPN servers globally still unpatched and in need of an upgrade.
- October 7, 2019 – The National Security Agency (NSA) produces a Cybersecurity Advisory on Pulse Secure and other VPN products being targeted actively by advanced persistent threat actors.
- October 16, 2019 – The CERT Coordination Center (CERT/CC) releases Vulnerability Note VU#927237: Pulse Secure VPN contains multiple vulnerabilities.
- January 2020 – Media reports cybercriminals now targeting unpatched Pulse Secure VPN servers to install REvil (Sodinokibi) ransomware.
A remote, unauthenticated attacker may be able to compromise a vulnerable VPN server. The attacker may be able to gain access to all active users and their plain-text credentials. It may also be possible for the attacker to execute arbitrary commands on each VPN client as it successfully connects to the VPN server.
- Pulse Connect Secure 9.0R1 - 9.0R3.3
- Pulse Connect Secure 8.3R1 - 8.3R7
- Pulse Connect Secure 8.2R1 - 8.2R12
- Pulse Connect Secure 8.1R1 - 8.1R15
- Pulse Policy Secure 9.0R1 - 9.0R3.1
- Pulse Policy Secure 5.4R1 - 5.4R7
- Pulse Policy Secure 5.3R1 - 5.3R12
- Pulse Policy Secure 5.2R1 - 5.2R12
- Pulse Policy Secure 5.1R1 - 5.1R15
This vulnerability has no viable workarounds except for applying the patches provided by the vendor and performing required system updates.
CISA strongly urges users and administrators to upgrade to the corresponding fixes. References
-  NIST NVD CVE-2019-11510
-  Pulse Secure Advisory SA44101
-  CERT/CC Vulnerability Note VU#927237
-  CISA Current Activity Vulnerabilities in Multiple VPN Applications
-  CISA Current Activity Multiple Vulnerabilities in Pulse Secure VPN
-  Pulse Secure Advisory SA44101
-  Pulse Secure Advisory SA44101
- January 10, 2020: Initial Version
The Cybersecurity and Infrastructure Security Agency (CISA) is sharing the following information with the cybersecurity community as a primer for assisting in the protection of our Nation’s critical infrastructure in light of the current tensions between the Islamic Republic of Iran and the United States and Iran’s historic use of cyber offensive activities to retaliate against perceived harm. Foremost, CISA recommends organizations take the following actions:
- Adopt a state of heightened awareness. This includes minimizing coverage gaps in personnel availability, more consistently consuming relevant threat intelligence, and making sure emergency call trees are up to date.
- Increase organizational vigilance. Ensure security personnel are monitoring key internal security capabilities and that they know how to identify anomalous behavior. Flag any known Iranian indicators of compromise and tactics, techniques, and procedures (TTPs) for immediate response.
- Confirm reporting processes. Ensure personnel know how and when to report an incident. The well-being of an organization’s workforce and cyber infrastructure depends on awareness of threat activity. Consider reporting incidents to CISA to help serve as part of CISA’s early warning system (see Contact Information section below).
- Exercise organizational incident response plans. Ensure personnel are familiar with the key steps they need to take during an incident. Do they have the accesses they need? Do they know the processes? Are your various data sources logging as expected? Ensure personnel are positioned to act in a calm and unified manner.
Iran has a history of leveraging asymmetric tactics to pursue national interests beyond its conventional capabilities. More recently, its use of offensive cyber operations is an extension of that doctrine. Iran has exercised its increasingly sophisticated capabilities to suppress both social and political perspectives deemed dangerous to Iran and to harm regional and international opponents.
Iranian cyber threat actors have continuously improved their offensive cyber capabilities. They continue to engage in more “conventional” activities ranging from website defacement, distributed denial of service (DDoS) attacks, and theft of personally identifiable information (PII), but they have also demonstrated a willingness to push the boundaries of their activities, which include destructive wiper malware and, potentially, cyber-enabled kinetic attacks.
The U.S. intelligence community and various private sector threat intelligence organizations have identified the Islamic Revolutionary Guard Corps (IRGC) as a driving force behind Iranian state-sponsored cyberattacks–either through contractors in the Iranian private sector or by the IRGC itself.Iranian Cyber Activity
According to open-source information, offensive cyber operations targeting a variety of industries and organizations—including financial services, energy, government facilities, chemical, healthcare, critical manufacturing, communications, and the defense industrial base—have been attributed, or allegedly attributed, to the Iranian government. The same reporting has associated Iranian actors with a range of high-profile attacks, including the following:
- Late 2011 to Mid-2013 – DDoS Targeting U.S. Financial Sector: In response to this activity, in March 2016, the U.S. Department of Justice indicted seven Iranian actors employed by companies performing work on behalf of the IRGC for conducting DDoS attacks primarily targeting the public-facing websites of U.S. banks. The attacks prevented customers from accessing their accounts and cost the banks millions of dollars in remediation. 
- August/September 2013 – Unauthorized Access to Dam in New York State: In response, in March 2016, the U.S. Department of Justice indicted one Iranian actor employed by a company performing work on behalf of the IRGC for illegally accessing the supervisory control and data acquisition (SCADA) systems of the Bowman Dam in Rye, New York. The access allowed the actor to obtain information regarding the status and operation of the dam. 
- February 2014 – Sands Las Vegas Corporation Hacked: Cyber threat actors hacked into the Sands Las Vegas Corporation in Las Vegas, Nevada, and stole customer data, including credit card data, Social Security Numbers, and driver’s license numbers. According to a Bloomberg article from December 2014, the attack also involved a destructive portion, in which the Sands Las Vegas Corporation’s computer systems were wiped. In September 2015, the U.S. Director of National Intelligence identified the Iranian government as the perpetrator of the attack in a Statement for the Record to the House Permanent Select Committee on Intelligence. 
- 2013 to 2017 – Cyber Theft Campaign on Behalf of IRGC: In response, in March 2018, the U.S. Justice Department indicted nine Iranian actors associated with the Mabna Institute for conducting a massive cyber theft campaign containing dozens of individual incidents, including “many on behalf of the IRGC.” The thefts targeted academic and intellectual property data as well as email account credentials. According to the indictment, the campaign targeted “144 U.S. universities, 176 universities across 21 foreign countries, 47 domestic and foreign private sector companies, the U.S. Department of Labor, the Federal Energy Regulatory Commission, the State of Hawaii, the State of Indiana, the United Nations, and the United Nations Children’s Fund.” 
The following is a composite of actionable technical recommendations for IT professionals and providers to reduce their overall vulnerability. These recommendations are not exhaustive; rather they focus on the actions that will likely have the highest return on investment. In general, CISA recommends two courses of action in the face of potential threat from Iranian actors: 1) vulnerability mitigation and 2) incident preparation.
- Disable all unnecessary ports and protocols. Review network security device logs and determine whether to shut off unnecessary ports and protocols. Monitor common ports and protocols for command and control activity.
- Enhance monitoring of network and email traffic. Review network signatures and indicators for focused operations activities, monitor for new phishing themes and adjust email rules accordingly, and follow best practices of restricting attachments via email or other mechanisms.
- Patch externally facing equipment. Focus on patching critical and high vulnerabilities that allow for remote code execution or denial of service on externally facing equipment.
- Log and limit usage of PowerShell. Limit the usage of PowerShell to only users and accounts that need it, enable code signing of PowerShell scripts, and enable logging of all PowerShell commands.
- Ensure backups are up to date and stored in an easily retrievable location that is air-gapped from the organizational network.
Manage the access control list for "Replicating Directory Changes" and other permissions associated with domain controller replication.
Consider disabling or restricting NTLM.
Ensure that local administrator accounts have complex, unique passwords across all systems on the network.
Limit credential overlap across accounts and systems by training users and administrators not to use the same password for multiple accounts.
- Windows: Monitor for unexpected processes interacting with Isass.exe.
- Linux: The AuditD monitoring tool can be used to watch for hostile processes opening a maps file in the proc file system, alerting on the pid, process name, and arguments for such programs.
- Consider utilizing the Antimalware Scan Interface (AMSI) on Windows 10 to analyze commands after being processed/interpreted.
- Windows: Monitor for unexpected processes interacting with Isass.exe.
- Linux: The AuditD monitoring tool can be used to watch for hostile processes opening a maps file in the proc file system, alerting on the pid, process name, and arguments for such programs.
- Network intrusion prevention or data loss prevention tools may be set to block specific file types from leaving the network over unencrypted channels.
- Process monitoring and monitoring for command-line arguments for known compression utilities.
- If the communications channel is unencrypted, compressed files can be detected in transit during exfiltration with a network intrusion detection or data loss prevention system analyzing file headers.
- Set PowerShell execution policy to execute only signed scripts.
- Remove PowerShell from systems when not needed, but a review should be performed to assess the impact to an environment, since it could be in use for many legitimate purposes and administrative functions.
- Disable/restrict the WinRM Service to help prevent uses of PowerShell for remote execution.
- Restrict PowerShell execution policy to administrators.
- If PowerShell is not used in an environment, looking for PowerShell execution may detect malicious activity.
- Monitor for loading and/or execution of artifacts associated with PowerShell specific assemblies, such as System. Management.Automation.dll (especially to unusual process names/locations).
- Turn on PowerShell logging to gain increased fidelity in what occurs during execution (which is applied to .NET invocations).
- Application whitelisting may be able to prevent the running of executables masquerading as other files.
- If a link is being visited by a user, network intrusion prevention systems and systems designed to scan and remove malicious downloads can be used to block activity.
- Block unknown or unused files in transit by default that should not be downloaded or by policy from suspicious sites as a best practice to prevent some vectors, such as .scr., .exe, .pif, .cpl, etc.
- Use user training as a way to bring awareness to common phishing and spearphishing techniques and how to raise suspicion for potentially malicious events.
- Monitor the execution of and command-line arguments for applications that may be used by an adversary to gain Initial Access that require user interaction. This includes compression applications, such as those for zip files that can be used to Deobfuscate/Decode Files or Information in payloads.
- Anti-virus can potentially detect malicious documents and files that are downloaded and executed on the user's computer.
- Endpoint sensing or network sensing can potentially detect malicious events once the file is opened (such as a Microsoft Word document or PDF reaching out to the internet or spawning Powershell.exe) for techniques such as Exploitation for Client Execution and Scripting.
- Configure Office security settings enable Protected View, to execute within a sandbox environment, and to block macros through Group Policy. Other types of virtualization and application microsegmentation may also mitigate the impact of compromise.
- Turn off unused features or restrict access to scripting engines such as VBScript or scriptable administration frameworks such as PowerShell.
- Examine scripting user restrictions. Evaluate any attempts to enable scripts running on a system that would be considered suspicious.
- Scripts should be captured from the file system when possible to determine their actions and intent.
- Monitor processes and command-line arguments for script execution and subsequent behavior.
- Analyze Office file attachments for potentially malicious macros.
- Office processes, such as winword.exe, spawning instances of cmd.exe, script application like wscript.exe or powershell.exe, or other suspicious processes may indicate malicious activity.
- This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
- Monitor Registry for changes to run keys that do not correlate with known software, patch cycles, etc.
- Monitor the start folder for additions or changes.
- Tools such as Sysinternals Autoruns may also be used to detect system changes that could be attempts at persistence, including listing the run keys' Registry locations and startup folders.
- To increase confidence of malicious activity, data and events should not be viewed in isolation, but as part of a chain of behavior that could lead to other activities, such as network connections made for Command and Control, learning details about the environment through Discovery, and Lateral Movement.
- Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary malware or unusual data transfer over known tools and protocols like FTP can be used to mitigate activity at the network level.
- Monitor for file creation and files transferred within a network over SMB.
- Monitor use of utilities, such as FTP, that does not normally occur.
- Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server).
- Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used.
- Determine if certain websites that can be used for spearphishing are necessary for business operations and consider blocking access if activity cannot be monitored well or if it poses a significant risk.
- Users can be trained to identify social engineering techniques and spearphishing emails with malicious links.
- URL inspection within email (including expanding shortened links) can help detect links leading to known malicious sites.
- Detonation chambers can be used to detect these links and either automatically go to these sites to determine if they're potentially malicious, or wait and capture the content if a user visits the link.
- Anti-virus can automatically quarantine suspicious files.
- Network intrusion prevention systems and systems designed to scan and remove malicious email attachments can be used to block activity.
- Block unknown or unused attachments by default that should not be transmitted over email as a best practice to prevent some vectors, such as .scr, .exe, .pif, .cpl, etc.
- Some email scanning devices can open and analyze compressed and encrypted formats, such as zip and rar that may be used to conceal malicious attachments in Obfuscated Files or Information.
- Users can be trained to identify social engineering techniques and spearphishing emails.
- Network intrusion detection systems and email gateways can be used to detect spearphishing with malicious attachments in transit.
- Detonation chambers may also be used to identify malicious attachments.
- Solutions can be signature and behavior based, but adversaries may construct attachments in a way to avoid these systems.
- Anti-virus can potentially detect malicious documents and attachments as they're scanned to be stored on the email server or on the user's computer.
CISA encourages recipients of this report to contribute any additional information that they may have related to this threat. For any questions related to this report, please contact CISA at
- 1-888-282-0870 (From outside the United States: +1-703-235-8832)
- CISAServiceDesk@cisa.dhs.gov (UNCLASS)
- email@example.com (SIPRNET)
- firstname.lastname@example.org (JWICS)
CISA encourages you to report any suspicious activity, including cybersecurity incidents, possible malicious code, software vulnerabilities, and phishing-related scams. Reporting forms can be found on the CISA homepage at http://www.us-cert.gov/.References
-  Department of Justice press release: Seven Iranians Working for Islamic Revolutionary Guard Corps-Affiliated Entities Charged for Conducting Coordinated Campaign of Cyber Attacks Against U.S. Financial Sector
-  Department of Justice press release: Seven Iranians Working for Islamic Revolutionary Guard Corps-Affiliated Entities Charged for Conducting Coordinated Campaign of Cyber Attacks Against U.S. Financial Sector
-  Bloomberg article: Now at the Sands Casino: An Iranian Hacker in Every Server
-  Department of Justice press release: Nine Iranians Charged With Conducting Massive Cyber Theft Campaign on Behalf of the Islamic Revolutionary Guard Corps
-  MITRE ATT&CK Framework
- CISA Insights: Increased Geopolitical Tensions and Threats
- January 6, 2019: Initial version
This Alert is the result of recent collaboration between Department of the Treasury Financial Sector Cyber Information Group (CIG) and the Department of the Treasury’s Financial Crimes Enforcement Network (FinCEN) to identify and share information with the financial services sector. Treasury and the Cybersecurity and Infrastructure Security Agency (CISA) are providing this report to inform the sector about the Dridex malware and variants. The report provides an overview of the malware, related activity, and a list of previously unreported indicators of compromise derived from information reported to FinCEN by private sector financial institutions. Because actors using Dridex malware and its derivatives continue to target the financial services sector, including financial institutions and customers, the techniques, tactics, and procedures contained in this report warrant renewed attention. Treasury and CISA encourage network security specialists to incorporate these indicators into existing Dridex-related network defense capabilities and planning. For information regarding the malicious cyber actors responsible for the development and distribution of the Dridex malware, see the Treasury press release, Treasury Sanctions Evil Corp, the Russia-Based Cybercriminal Group Behind Dridex Malware.
This Alert does not introduce a new regulatory interpretation, nor impose any new requirements on regulated entities. Except where noted, there is no indication that the actual owner of the email address was involved in the suspicious or malicious activity. If activity related to these indicators of compromise is detected, please notify appropriate law enforcement and the CIG.
For a downloadable copy of IOCs, see:
The Dridex malware, and its various iterations, has the capability to impact confidentiality of customer data and availability of data and systems for business processes. According to industry reporting, the original version of Dridex first appeared in 2012, and by 2015 had become one of the most prevalent financial Trojans. We expect actors using Dridex malware and its derivatives to continue targeting the financial services sector, including both financial institutions and customers.Dridex-related Phishing Attributes
Actors typically distribute Dridex malware through phishing e-mail spam campaigns. Phishing messages employ a combination of legitimate business names and domains, professional terminology, and language implying urgency to persuade victims to activate open attachments. Sender e-mail addresses can simulate individuals (email@example.com), administrative (firstname.lastname@example.org, email@example.com), or common “do not reply” local parts (firstname.lastname@example.org). Subject and attachment titles can include typical terms such as “invoice”, “order”, “scan”, “receipt”, “debit note”, “itinerary”, and others.
The e-mail messages vary widely. The e-mail body may contain no text at all, except to include attachments with names that are strings of numbers, apparently relying on the subject line and victim curiosity to coerce the opening of the malicious file. Where there is a message body, the body may specifically state that the contents of the e-mail underwent virus scanning or simply directs the victim toward the link or attachment. In other cases, the body may include a long, substantive message, providing multiple points of contact and context for the malicious attachment. Attachment and hyperlink names vary from random sets of numbers or imitation automatic filenames from scanners to filenames purporting to reference financial records. Attachments may or may not have direct references using the same file name or strings of numbers in the bodies of the e-mails.
Example Links and Filenames (Note: link information is representative. Italicized statements are automatically generated by the cloud storage provider. # represents a random number.):
- Link: HTTPS://WWW.GOOGLE[.]COM/URL?Q=HTTPS://WWW.(Cloud Services Provider)[.]COM/S/(Cloud Account Value) /RECENT%20WIRE%20PAYMENT %######.SCR?(Cloud Provided Sequence)
Link: HTTPS://WWW.GOOGLE[.]COM/URL?Q=HTTPS://WWW.(Cloud Services Provider) [.]COM/S/ Cloud Account Value/AUTOMATEDCLEARINGHOUSE%20 PAYMENT####.DOC? (Cloud Provided Sequence)
Link: Malicious File: ID201NLD0012192016.DOC
By default, software generally prevents execution of macros without user permission. Attached files, particularly .doc and .xls files, contain instructions on how a user should enable content and specifically macros, effectively using social engineering to facilitate the download. Malicious files sometimes even include screenshots of the necessary actions to enable macros.Malware Capabilities
Dridex malware operates from multiple modules that may be downloaded together or following the initial download of a “loader” module. Modules include provisions for capturing screenshots, acting as a virtual machine, or incorporating the victim machine into a botnet. Through its history and development, Dridex has used several exploits and methods for execution, including modification of directory files, using system recovery to escalate privileges, and modification of firewall rules to facilitate peer-to-peer communication for extraction of data. Recent versions of Dridex exploit vulnerability CVE-2017-0199, which allows remote execution of code. This vulnerability is specific to Microsoft Office and WordPad. Microsoft released a patch in 2017.
Once downloaded and active, Dridex has a wide range of capabilities, from downloading additional software to establishing a virtual network to deletion of files. The primary threat to financial activity is the Dridex’s ability to infiltrate browsers, detect access to online banking applications and websites, and inject malware or keylogging software, via API hooking, to steal customer login information. Dridex modules package, encrypt, and transmit captured information, screenshots, etc., via peer-to-peer (P2P) networks in the XML format or in binary format, as seen in newer versions. After stealing the login data, the attackers have the potential to facilitate fraudulent automated clearing house (ACH) and wire transfers, open fraudulent accounts, and potentially adapt victim accounts for other scams involving business e-mail compromise or money mule activity.
The Dridex malware has evolved through several versions since its inception, partially to adapt to updated browsers. Although the characteristics described reflect some of the most recent configurations, actors continue to identify and exploit vulnerabilities in widely used software.Dridex Malware and Variants
While Dridex is among the most prevalent sources of infection, previous variants and similar malware continue to represent a threat. Dridex is itself an improved variant of the Cridex and Bugat Trojans that preceded it, and it shares some of their codes. Although the previous variants’ theft activities operate in mostly the same way, the P2P communication aspects of Dridex improve its concealment and redundancy.Ransomware
Actors distributing Dridex likely employ ransomware with similar configurations. Code for BitPaymer, also known as Friedex, includes numerous similarities to Dridex, despite its function as ransomware rather than data extraction. The two malwares use the same mechanics for several functions, and the authors compiled the codes at nearly the same time. The ransomware distributed through these malwares has targeted U.S. financial institutions and resulted in data and financial loss.
Locky ransomware operates using the same delivery method for the downloader, with similar subject lines and attachments. Attackers also use the same botnets to deliver both Dridex and Locky ransomware, sometimes simultaneously. Variants of Locky include Zepto and Osiris. Locky ransomware and its variants have a wide footprint, with varying impact depending on victim IT policies and practices and network configurations.
Although the highest infection rates took place in late 2015 and early 2016, concurrent with Locky ransomware distribution, Dridex continues to impact numerous countries. The Dridex hackers appear to direct the majority of attacks at English-speaking countries. Cybersecurity industry reporting attributes Dridex, BitPaymer, and Locky campaigns, as well as other massive malware spam (malspam) campaigns to actors known alternately as Evil Corp or TA505. (Note: some cybersecurity industry reporting simply refers to the actors as “Dridex” or the “Dridex hackers.”) Actors distribute the malware via massive spam campaigns, sending up to millions of messages per day, although volume of messages varies widely.Indicators of Compromise
The following indicators are associated with the activity described in this report:Indicator Type Indicator Value Associated Activity Email address info[@]antonioscognamiglio[.]it Dridex Email address info[@]golfprogroup[.]com Dridex Email address cariola72[@]teletu[.]it Dridex Email address faturamento[@]sudestecaminhoes[.]com.br Dridex Email address info[@]melvale[.]co.uk Dridex Email address fabianurquiza[@]correo.dalvear[.]com.ar Dridex Email address web1587p16[@]mail.flw-buero[.]at Dridex Email address bounce[@]bestvaluestore[.]org Dridex Email address farid[@]abc-telecom[.]az Dridex Email address bounce[@]bestvaluestore[.]org Dridex Email address admin[@]sevpazarlama[.]com Dridex Email address faturamento[@]sudestecaminhoes[.]com.br Dridex Email address pranab[@]pdrassocs[.]com Dridex Email address tom[@]blackburnpowerltd[.]co.uk Dridex Email address yportocarrero[@]elevenca[.]com Dridex Email address s.palani[@]itifsl.co[.]in Dridex Email address faber[@]imaba[.]nl Dridex Email address admin[@]belpay[.]by Dridex IP address 62[.]149[.]158[.]252 Dridex IP address 177[.]34[.]32[.]109 Dridex IP address 2[.]138[.]111[.]86 Dridex IP address 122[.]172[.]96[.]18 Dridex IP address 69[.]93[.]243[.]5 Dridex IP address 200[.]43[.]183[.]102 Dridex IP address 79[.]124[.]76[.]30 Dridex IP address 188[.]125[.]166[.]114 Dridex IP address 37[.]59[.]52[.]64 Dridex IP address 50[.]28[.]35[.]36 Dridex IP address 154[.]70[.]39[.]158 Dridex IP address 108[.]29[.]37[.]11 Dridex IP address 65[.]112[.]218[.]2 Dridex
Treasury and CISA encourage users and organizations to:
- Contact law enforcement immediately report regarding any identified activity related to Dridex malware or its derivatives. Please see contact information for FBI and CISA at the end of this report.
- Incorporate the indicators of compromise identified in this report into intrusion detection systems and security alert systems to enable active blocking or reporting of suspected malicious activity. Note that the above list is not a comprehensive list of all indicators associated with this activity.
- Report suspicious activity, highlighting the presence of “Cyber Event Indicators.” Indicators of Compromise, such as suspicious e-mail addresses, file names, hashes, domains, and IP addresses, can be provided under Item 44 of the Suspicious Activity Report (SAR) form. FinCEN welcomes voluntary SAR filing in circumstances where reporting is not required.
The following mitigation recommendations respond directly to Dridex TTPs:
- Ensuring systems are set by default to prevent execution of macros.
- Inform and educate employees on the appearance of phishing messages, especially those used by the hackers for distribution of malware in the past.
- Update intrusion detection and prevention systems frequently to ensure the latest variants of malware and downloaders are included.
- Conduct regular backup of data, ensuring backups are protected from potential ransomware attack.
- Exercise employees’ response to phishing messages and unauthorized intrusion.
- If there is any doubt about message validity, call and confirm the message with the sender using a number or e-mail address already on file.
- Treasury and CISA remind users and administrators to 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 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.
- Exercise cybersecurity procedures and continuity of operations plans to enhance and maintain ability to respond during and following a cyber incident.
The National Institute of Standards and Technology (NIST) has published additional information on malware incident prevention and handling in their Special Publication 800-83, Guide to Malware Incident Prevention and Handling for Desktops and Laptops:
The National Security Agency (NSA) recently published its Top Ten Cybersecurity Mitigation Strategies (This is the current website for Top 10 mitigation strategies: https://www.nsa.gov/Portals/70/documents/what-we-do/cybersecurity/professional-resources/csi-nsas-top10-cybersecurity-mitigation-strategies.pdf?v=1). Aligned with the NIST Cybersecurity Framework, the Strategies offer a risk-based approach to mitigating exploitation techniques used by Advance Persistent Threat (APT) actors.
The Strategies counter a broad range of exploitation techniques used by malicious cyber actors. NSA’s mitigations set priorities for enterprise organizations to minimize mission impact. The mitigations also build upon the NIST Cybersecurity Framework functions to manage cybersecurity risk and promote a defense-in-depth security posture. The mitigation strategies are ranked by effectiveness against known APT tactics. Additional strategies and best practices will be required to mitigate the occurrence of new tactics.
- Update and Upgrade Software Immediately. Apply all available software updates, automate the process to the extent possible, and use an update service provided directly from the vendor. Automation is necessary because threat actors study patches and create exploits, often soon after a patch is released. These “N-day” exploits can be as damaging as a zero-day. Vendor updates must also be authentic; updates are typically signed and delivered over protected links to assure the integrity of the content. Without rapid and thorough patch application, threat actors can operate inside a defender’s patch cycle.
- Defend Privileges and Accounts. Assign privileges based on risk exposure and as required to maintain operations. Use a Privileged Access Management (PAM) solution to automate credential management and fine-grained access control. Another way to manage privilege is through tiered administrative access in which each higher tier provides additional access, but is limited to fewer personnel. Create procedures to securely reset credentials (e.g., passwords, tokens, tickets). Privileged accounts and services must be controlled because threat actors continue to target administrator credentials to access high-value assets, and to move laterally through the network.
- Enforce Signed Software Execution Policies. Use a modern operating system that enforces signed software execution policies for scripts, executables, device drivers, and system firmware. Maintain a list of trusted certificates to prevent and detect the use and injection of illegitimate executables. Execution policies, when used in conjunction with a secure boot capability, can assure system integrity. Application Whitelisting should be used with signed software execution policies to provide greater control. Allowing unsigned software enables threat actors to gain a foothold and establish persistence through embedded malicious code.
- Exercise a System Recovery Plan. Create, review, and exercise a system recovery plan to ensure the restoration of data as part of a comprehensive disaster recovery strategy. The plan must protect critical data, configurations, and logs to ensure continuity of operations due to unexpected events. For additional protection, backups should be encrypted, stored offsite, offline when possible, and support complete recovery and reconstitution of systems and devices. Perform periodic testing and evaluate the backup plan. Update the plan as necessary to accommodate the ever-changing network environment. A recovery plan is a necessary mitigation for natural disasters as well as malicious threats including ransomware.
- Actively Manage Systems and Configurations. Take inventory of network devices and software. Remove unwanted, unneeded, or unexpected hardware and software from the network. Starting from a known baseline reduces the attack surface and establishes control of the operational environment. Thereafter, actively manage devices, applications, operating systems, and security configurations. Active enterprise management ensures that systems can adapt to dynamic threat environments while scaling and streamlining administrative operations.
- Continuously Hunt for Network Intrusions. Take proactive steps to detect, contain, and remove any malicious presence within the network. Enterprise organizations should assume that a compromise has taken place and use dedicated teams to continuously seek out, contain, and remove threat actors within the network. Passive detection mechanisms, such as logs, Security Information and Event Management (SIEM) products, Endpoint Detection and Response (EDR) solutions, and other data analytic capabilities are invaluable tools to find malicious or anomalous behaviors. Active pursuits should also include hunt operations and penetration testing using well documented incident response procedures to address any discovered breaches in security. Establishing proactive steps will transition the organization beyond basic detection methods, enabling real-time threat detection and remediation using a continuous monitoring and mitigation strategy.
- Leverage Modern Hardware Security Features. Use hardware security features like Unified Extensible Firmware Interface (UEFI) Secure Boot, Trusted Platform Module (TPM), and hardware virtualization. Schedule older devices for a hardware refresh. Modern hardware features increase the integrity of the boot process, provide system attestation, and support features for high-risk application containment. Using a modern operating system on outdated hardware results in a reduced ability to protect the system, critical data, and user credentials from threat actors.
- Segregate Networks Using Application-Aware Defenses. Segregate critical networks and services. Deploy application-aware network defenses to block improperly formed traffic and restrict content, according to policy and legal authorizations. Traditional intrusion detection based on known-bad signatures is quickly decreasing in effectiveness due to encryption and obfuscation techniques. Threat actors hide malicious actions and remove data over common protocols, making the need for sophisticated, application-aware defensive mechanisms critical for modern network defenses.
- Integrate Threat Reputation Services. Leverage multi-sourced threat reputation services for files, DNS, URLs, IPs, and email addresses. Reputation services assist in the detection and prevention of malicious events and allow for rapid global responses to threats, a reduction of exposure from known threats, and provide access to a much larger threat analysis and tipping capability than an organization can provide on its own. Emerging threats, whether targeted or global campaigns, occur faster than most organizations can handle, resulting in poor coverage of new threats. Multi-source reputation and information sharing services can provide a more timely and effective security posture against dynamic threat actors.
- Transition to Multi-Factor Authentication. Prioritize protection for accounts with elevated privileges, remote access, and/or used on high value assets. Physical token-based authentication systems should be used to supplement knowledge-based factors such as passwords and PINs. Organizations should migrate away from single factor authentication, such as password-based systems, which are subject to poor user choices and susceptible to credential theft, forgery, and reuse across multiple systems.
Reporting Suspected Malicious Activity
To report an intrusion and request resources for incident response or technical assistance, contact CISA (CISAservicedesk@hq.dhs.gov or 888-282-0870), FBI through a local field office (https://www.fbi.gov/contact-us/field-offices), or FBI’s Cyber Division (CyWatch@fbi.gov or 855-292-3937).
Institutions should determine whether filing of a Suspicious Activity Report (“SAR”) is required under Bank Secrecy Act regulations. In instances where filing is not required, institutions may file a SAR voluntarily to aid FinCEN and law enforcement efforts in protecting the financial sector. Financial institutions are encouraged to provide relevant cyber-related information and indicators in their SAR reporting. For questions regarding cyber SAR filing, please contact the FinCEN Resource Center (FRC@fincen.gov or 1-800-767-2825).Open-Source Reporting On Dridex
The following represents an alphabetized selection of open-source reporting by U.S. government and industry sources on Dridex malware and its derivatives:
- “Dridex P2P Malware,” US-CERT Alert (TA15-286A), https://www.us-cert.gov/ncas/alerts/TA15-286A, 13 October 2015.
- “Dridex Threat Profile,” New Jersey Cybersecurity & Communications Integration Cell, https://www.cyber.nj.gov/threat-profiles/trojan-variants/dridex, accessed 15 April 2019.
- Alert Logic, “Dridex malware has evolved to Locky Ransomware,” No date, https://www.alertlogic.com/resources/threat-reports/dridex-malware-has-evolved-to-locky-ransomware/, accessed 11 March 2019.
- Avast Blog, “A closer look at the Locky ransomware,” 10 March 2016, https://blog.avast.com/a-closer-look-at-the-locky-ransomware, accessed 6 February 2019.
- Brett Stone-Gross, Ph.D., “Dridex (Bugat v5) Botnet Takeover Operation, Secureworks, 13 October 2015, https://www.secureworks.com/research/dridex-bugat-v5-botnet-takeover-operation, accessed 6 February 2019.
- Brewster, Thomas, “Cops Knock Down Dridex Malware that Earned ‘Evil Corp’ Cybercriminals At Least $50 Million,” Forbes, 13 October 2015, https://www.forbes.com/sites/thomasbrewster/2015/10/13/dridex-botnet-takedown/#2b883f00415b.
- Chandler, Andy, “FBI announces Dridex gang indictment and praises Fox-IT,” Fox-IT, 13 October 2015, https://www.fox-it.com/en/about-fox-it/corporate/news/fbi-announces-dridex-gang-indictments-praises-fox/, accessed 7 February 2019.
- DHS CISA, “Alert (TA15-286A), Dridex P2P Malware,” https://www.us-cert.gov/ncas/alerts/TA15-286A, accessed 4 June 2019.
- Eduard Kovacs, “Dridex still active after takedown attempt,” Security Week, 19 October 2015, https://www.securityweek.com/dridex-still-active-after-takedown-attempt, accessed 11 March 2019.
- Geoff White, “How the Dridex Gang makes millions from bespoke ransomware,” Forbes, 26 September 2018, https://www.forbes.com/sites/geoffwhite/2018/09/26/how-the-dridex-gang-makes-millions-from-bespoke-ransomware/, accessed 11 March 2019.
- MS-ISAC, “Cybercrime Technical Desk Reference,” 31 August 2018, https://www.cisecurity.org/wp-content/uploads/2018/09/MS-ISAC-Cyber-Crime-Technical-Desk-Reference.pdf, accessed 6 February 2019.
- O’Brien, Dick. “Dridex: Tidal waves of spam pushing dangerous financial Trojan,” Symantec, February 2016, http://www.symantec.com/content/en/us/enterprise/media/security_response/whitepapers/dridex-financial-trojan.pdf, accessed 4 February 2019.
- Poslušný, Michal, “FriedEx: BitPaymer ransomware the work of Dridex authors, welivesecurity by ESET, 26 January 2018, https://www.welivesecurity.com/2018/01/26/friedex-bitpaymer-ransomware-work-dridex-authors/, accessed 6 February 2019.
- Proofpoint, “Dridex Campaigns Hitting Millions of Recipients Using Unpatched Microsoft Zero-Day,” https://www.proofpoint.com/us/threat-insight/post/dridex-campaigns-millions-recipients-unpatched-microsoft-zero-day, accessed 5 February 2019.
- Proofpoint, “High-Volume Dridex Banking Trojan Campaigns Return.” https://www.proofpoint.com/us/threat-insight/post/high-volume-dridex-campaigns-return, accessed 1 February 2019.
- Proofpoint, “Threat Actor Profile: TA505, From Dridex to GlobeImposter,” https://www.proofpoint.com/us/threat-insight/post/threat-actor-profile-ta505-dridex-globeimposter, accessed 6 February 2019.
- Roland Dela Paz and Ran Mosessco. “New year, new look – Dridex via compromised FTP,” ForcePoint, 18 January 2018, https://blogs.forcepoint.com/blog/security-labs/new-year-new-look-dridex-compromised-ftp, accessed 4 February 2019.
- Sanghavi, Mithun. “DRIDEX and how to overcome it.” Symantec Official Blog, 30 March 2015, https://www.symantec.com/connect/blogs/dridex-and-how-overcome-it, accessed 4 February 2019.
- Security Intelligence Blog, “URSNIF, EMOTET, DRIDEX and BitPaymer Gangs Linked by a Similar Loader,” Trend Micro, 18 December 2018, https://blog.trendmicro.com/trendlabs-security-intelligence/ursnif-emotet-dridex-and-bitpaymer-gangs-linked-by-a-similar-loader/, accessed 6 February 2019.
- Talos Group, “Threat Spotlight: Spam Served With a Side of Dridex,” Cisco Blogs, 6 April 2015, https://blogs.cisco.com/security/talos/spam-dridex, accessed 4 February 2019.
- December 5, 2019: Initial version
On January 14, 2020, Microsoft will end extended support for their Windows 7 and Windows Server 2008 R2 operating systems. After this date, these products will no longer receive free technical support, or software and security updates.
Organizations that have regulatory obligations may find that they are unable to satisfy compliance requirements while running Windows 7 and Windows Server 2008 R2.Technical Details
All software products have a lifecycle. “End of support” refers to the date when the software vendor will no longer provide automatic fixes, updates, or online technical assistance. 
For more information on end of support for Microsoft products see the Microsoft End of Support FAQ.
Systems running Windows 7 and Windows Server 2008 R2 will continue to work at their current capacity even after support ends on January 14, 2020. However, using unsupported software may increase the likelihood of malware and other security threats. Mission and business functions supported by systems running Windows 7 and Windows Server 2008 R2 could experience negative consequences resulting from unpatched vulnerabilities and software bugs. These negative consequences could include the loss of confidentiality, integrity, and availability of data, system resources, and business assets.Mitigations
The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and organizations to:
- Upgrade to a newer operating system.
- Identify affected devices to determine breadth of the problem and assess risk of not upgrading.
- Establish and execute a plan to systematically migrate to currently supported operating systems or employ a cloud-based service.
- Contact the operating system vendor to explore opportunities for fee-for-service maintenance, if unable to upgrade.
-  Microsoft End of Support FAQ
-  Microsoft Windows Lifecyle Fact Sheet
-  Microsoft Windows Upgrade and Migration Considerations
-  ComputerWorld: Leaving Windows 7? Here are Some non-Windows Options
-  CISA Analysis Report AR19-133A: Microsoft Office 365 Security Observations
- October 17, 2019: Initial version