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Oracle Releases October 2020 Security Bulletin

US-Cert Current Activity - Tue, 10/20/2020 - 7:20pm
Original release date: October 20, 2020

Oracle has released its Critical Patch Update for October 2020 to address 402 vulnerabilities across multiple products. A remote attacker could exploit some of these vulnerabilities to take control of an affected system.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review the Oracle October 2020 Critical Patch Update and apply the necessary updates.

This product is provided subject to this Notification and this Privacy & Use policy.

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NSA Releases Advisory on Chinese State-Sponsored Actors Exploiting Publicly Known Vulnerabilities

US-Cert Current Activity - Tue, 10/20/2020 - 3:23pm
Original release date: October 20, 2020

The National Security Agency (NSA) has released a cybersecurity advisory on Chinese state-sponsored malicious cyber activity. This advisory provides 25 Common Vulnerabilities and Exposures (CVEs) known to be recently leveraged, or scanned-for, by Chinese state-sponsored cyber actors to enable successful hacking operations against a multitude of victim networks.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages critical system administrators to prioritize the immediate patching of the CVEs in NSA’s advisory and to review CISA’s Alert Potential for China Cyber Response to Heightened U.S.–China Tensions, which details potential cyber response to heightened tensions between the United States and China and provides specific tactics, techniques, and procedures (TTPs) and recommended mitigations to the cybersecurity community to assist in the protection of our Nation’s critical infrastructure.

Review the CISA's Chinese Malicious Cyber Activity page for more information on Chinese malicious cyber activity.

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VMware Releases Security Updates for Multiple Products

US-Cert Current Activity - Tue, 10/20/2020 - 12:44pm
Original release date: October 20, 2020

VMware has released security updates to address vulnerabilities affecting multiple products. A remote attacker could exploit one of these vulnerabilities to take control of an affected system.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review VMware Security Advisory VMSA-2020-0023 and apply the necessary updates or workarounds.

This product is provided subject to this Notification and this Privacy & Use policy.

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Microsoft Releases Security Updates to Address Remote Code Execution Vulnerabilities

US-Cert Current Activity - Fri, 10/16/2020 - 2:26pm
Original release date: October 16, 2020

Microsoft has released security updates to address remote code execution vulnerabilities affecting Windows Codecs Library and Visual Studio Code. An attacker could exploit these vulnerabilities to take control of an affected system.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review the Microsoft security advisories for CVE-2020-17022 and CVE-2020-17023 and apply the necessary updates.

 

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NCSC Releases Alert on Microsoft SharePoint Vulnerability

US-Cert Current Activity - Fri, 10/16/2020 - 1:03pm
Original release date: October 16, 2020

The United Kingdom (UK) National Cyber Security Centre (NCSC) has released an Alert to address a vulnerability—CVE-2020-16952—affecting Microsoft SharePoint server. An attacker could exploit this vulnerability to take control of an affected system. Applying patches from Microsoft’s October 2020 Security Advisory for CVE-2020-16952 can prevent exploitation of this vulnerability.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages administrators to review the NCSC Alert and the Microsoft Security Advisory for CVE-202016952 for more information.

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Adobe Releases Security Updates for Magento

US-Cert Current Activity - Fri, 10/16/2020 - 12:10pm
Original release date: October 16, 2020

Adobe has released security updates to address vulnerabilities affecting Magento Commerce and Magento Open Source. An attacker could exploit some of these vulnerabilities to take control of an affected system.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review Adobe Security Bulletin APSB20-59 and apply the necessary updates.

This product is provided subject to this Notification and this Privacy & Use policy.

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Juniper Networks Releases Security Updates for Multiple Products

US-Cert Current Activity - Thu, 10/15/2020 - 11:12am
Original release date: October 15, 2020

Juniper Networks has released security updates to address vulnerabilities affecting multiple products. An attacker could exploit some of these vulnerabilities to take control of an affected system.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review the Juniper Networks security advisories page and apply the necessary updates.

This product is provided subject to this Notification and this Privacy & Use policy.

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Microsoft Addresses Windows TCP/IP RCE/DoS Vulnerability

US-Cert Current Activity - Wed, 10/14/2020 - 11:59am
Original release date: October 14, 2020

Microsoft has released a security update to address a protocol vulnerability—CVE-2020-16898—in Windows Transmission Control Protocol (TCP)/IP stack handling of Internet Control Message Protocol version 6 (ICMPv6) Router Advertisement packets. A remote attacker could exploit this vulnerability to take control of an affected system or cause a denial-of-service condition.
 
The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review Microsoft’s Security Advisory for more information, and apply the necessary updates or workaround.
 

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Adobe Releases Security Updates for Flash Player

US-Cert Current Activity - Wed, 10/14/2020 - 9:11am
Original release date: October 14, 2020

Adobe has released security updates to address a vulnerability affecting Flash Player. An attacker could exploit this vulnerability to take control of an affected system.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review Adobe Security Bulletin APSB20-58 and apply the necessary update.

This product is provided subject to this Notification and this Privacy & Use policy.

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Apache Releases Security Updates for Apache Tomcat

US-Cert Current Activity - Wed, 10/14/2020 - 9:06am
Original release date: October 14, 2020

The Apache Software Foundation has released a security advisory to address a vulnerability in Apache Tomcat. An attacker could exploit this vulnerability to obtain sensitive information. 

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review Apache Security Advisory for CVE-2020-13943 and upgrade to the appropriate version.

This product is provided subject to this Notification and this Privacy & Use policy.

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Microsoft Releases October 2020 Security Updates

US-Cert Current Activity - Tue, 10/13/2020 - 2:42pm
Original release date: October 13, 2020

Microsoft has released updates to address vulnerabilities in Microsoft software. A remote attacker could exploit some of these vulnerabilities to take control of an affected system.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review Microsoft’s October 2020 Security Update Summary and Deployment Information and apply the necessary updates.

This product is provided subject to this Notification and this Privacy & Use policy.

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SAP Releases October 2020 Security Updates

US-Cert Current Activity - Tue, 10/13/2020 - 12:41pm
Original release date: October 13, 2020

SAP has released security updates to address vulnerabilities affecting multiple products. An attacker could exploit some of these vulnerabilities to take control of an affected system. This includes an OS command injection vulnerability (CVE-2020-6364) affecting SAP Solution Manager and SAP Focused Run.
 
The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review the SAP Security Notes for October 2020 and apply the necessary updates.

This product is provided subject to this Notification and this Privacy & Use policy.

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CISA and FBI Release Joint Advisory Regarding APT Actors Chaining Vulnerabilities Against SLTT, Critical Infrastructure, and Elections Organizations

US-Cert Current Activity - Fri, 10/09/2020 - 6:20pm
Original release date: October 9, 2020

The Cybersecurity and Information Security Agency (CISA) and the Federal Bureau of Information (FBI) have released a joint cybersecurity advisory regarding advanced persistent threat (APT) actors chaining vulnerabilities—a commonly used tactic exploiting multiple vulnerabilities in the course of a single intrusion—in an attempt to compromise federal and state, local, tribal, and territorial (SLTT) government networks, critical infrastructure, and elections organizations. CISA is aware of some instances where this activity resulted in unauthorized access to elections support systems; however, CISA has no evidence to date that integrity of elections data has been compromised.

The joint cybersecurity advisory contains information on exploited vulnerabilities and recommended mitigation actions for affected organizations to pursue.

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AA20-283A: APT Actors Chaining Vulnerabilities Against SLTT, Critical Infrastructure, and Elections Organizations

US-Cert Alerts - Fri, 10/09/2020 - 4:21pm
Original release date: October 9, 2020
Summary

This joint cybersecurity advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework. See the ATT&CK for Enterprise framework for all referenced threat actor techniques.

Note: the analysis in this joint cybersecurity advisory is ongoing, and the information provided should not be considered comprehensive. The Cybersecurity and Information Security Agency (CISA) will update this advisory as new information is available.

This joint cybersecurity advisory was written by CISA with contributions from the Federal Bureau of Investigation (FBI). 

CISA has recently observed advanced persistent threat (APT) actors exploiting multiple legacy vulnerabilities in combination with a newer privilege escalation vulnerability—CVE-2020-1472—in Windows Netlogon. The commonly used tactic, known as vulnerability chaining, exploits multiple vulnerabilities in the course of a single intrusion to compromise a network or application. 

This recent malicious activity has often, but not exclusively, been directed at federal and state, local, tribal, and territorial (SLTT) government networks. Although it does not appear these targets are being selected because of their proximity to elections information, there may be some risk to elections information housed on government networks.

CISA is aware of some instances where this activity resulted in unauthorized access to elections support systems; however, CISA has no evidence to date that integrity of elections data has been compromised. There are steps that election officials, their supporting SLTT IT staff, and vendors can take to help defend against this malicious cyber activity.

Some common tactics, techniques, and procedures used by APT actors include leveraging legacy network access and virtual private network (VPN) vulnerabilities in association with the recent critical CVE-2020-1472 Netlogon vulnerability. CISA is aware of multiple cases where the Fortinet FortiOS Secure Socket Layer (SSL) VPN vulnerability CVE-2018-13379 has been exploited to gain access to networks. To a lesser extent, CISA has also observed threat actors exploiting the MobileIron vulnerability CVE-2020-15505. While these exploits have been observed recently, this activity is ongoing and still unfolding. CISA recommends network staff and administrators review internet-facing infrastructure for vulnerabilities, including Juniper CVE-2020-1631, Pulse Secure CVE-2019-11510,  Citrix NetScaler CVE-2020-19781, and Palo Alto Networks CVE-2020-2012 (this list is not considered exhaustive).

After gaining initial access, the actors exploit CVE-2020-1472 to compromise all Active Directory (AD) identity services. Actors have then been observed using legitimate remote access tools, such as VPN and Remote Desktop Protocol (RDP), to access the environment with the compromised credentials. Observed activity targets multiple sectors, and is not limited to SLTT entities.

Click here for a PDF version of this report.

Technical DetailsInitial Access

APT threat actors are actively leveraging legacy vulnerabilities in internet-facing infrastructure (Exploit Public-Facing Application [T1190], External Remote Services [T1133]) to gain initial access into systems. The APT actors appear to have predominately gained initial access via the Fortinet FortiOS VPN vulnerability CVE-2018-13379; however, other vulnerabilities, listed below, have been observed (as analysis is evolving, these listed vulnerabilities should not be considered comprehensive).

  • Citrix NetScaler CVE-2020-19781
  • MobileIron CVE-2020-15505
  • Pulse Secure CVE-2019-11510
  • Palo Alto Networks CVE-2020-2012
  • F5 BIG-IP CVE-2020-5902
FortiGuard ForitOS SSL VPN CVE-2018-13379

CVE-2018-13379 is a path traversal vulnerability in the FortiOS SSL VPN web portal. An unauthenticated attacker could exploit this vulnerability to download FortiOS system files through specially crafted HTTP resource requests.

MobileIron Core & Connector Vulnerability CVE-2020-15505

CVE-202-15505 is a remote code execution vulnerability in MobileIron Core & Connector versions 10.3 and earlier. This vulnerability allows an external attacker, with no privileges, to execute code of their choice on the vulnerable system. As mobile device management (MDM) systems are critical to configuration management for external devices, they are usually highly permissioned and make a valuable target for threat actors.

Privilege Escalation

Post initial access, the APT actors use multiple techniques to expand access to the environment. The actors are leveraging CVE-2020-1472 in Windows Netlogon to escalate privileges and obtain access to Windows AD servers. Actors are also leveraging the opensource tools such as Mimikatz and the CrackMapExec tool to obtain Valid Account [T1078] credentials from AD servers.

Microsoft Netlogon Remote Protocol Vulnerability: CVE-2020-1472

CVE-2020-1472 is a vulnerability in Microsoft Windows Netlogon Remote Protocol (MS-NRPC), a core authentication component of Active Directory. This vulnerability could allow an unauthenticated attacker with network access to a domain controller to completely compromise all AD identity services (Valid Accounts: Domain Accounts [T1078.002]). Malicious actors can leverage this vulnerability to compromise other devices on the network (Lateral Movement [TA0008]).

Persistence

Once system access has been achieved, the APT actors use abuse of legitimate credentials (Valid Account [T1078]) to log in via VPN or Remote Access Services [T1133] to maintain persistence.

Mitigations

Organizations with externally facing infrastructure devices that have the vulnerabilities listed in this joint cybersecurity advisory, or other vulnerabilities, should move forward with an “assume breach” mentality. As initial exploitation and escalation may be the only observable exploitation activity, most mitigations will need to focus on more traditional network hygiene and user management activities.

Keep Systems Up to Date

Patch systems and equipment promptly and diligently. Establishing and consistently maintaining a thorough patching cycle continues to be the best defense against adversary TTPs. See table 1 for patch information on CVEs mentioned in this report.

Table 1: Patch information for exploited CVEs

Vulnerability Vulnerable Products Patch Information CVE-2018-13379
  • FortiOS 6.0
  • FortiOS 5.6  
  • FortiOS 5.4
CVE-2019-19781
  • Citrix Application Delivery Controller
  • Citrix Gateway
  • Citrix SDWAN WANOP
CVE-2020-5902
  • Big-IP devices (LTM, AAM, Advanced WAF, AFM, Analytics, APM, ASM, DDHD, DNS, FPS, GTM, Link Controller, PEM, SSLO, CGNAT)
CVE-2020-11510
  • Pulse Connect Secure 9.0R1 - 9.0R3.3, 8.3R1 - 8.3R7, 8.2R1 - 8.2R12, 8.1R1 - 8.1R15
  • Pulse Policy Secure 9.0R1 - 9.0R3.1, 5.4R1 - 5.4R7, 5.3R1 - 5.3R12, 5.2R1 - 5.2R12, 5.1R1 - 5.1R15
CVE-2020-15505
  • MobileIron Core & Connector versions 10.3.0.3 and earlier, 10.4.0.0, 10.4.0.1, 10.4.0.2, 10.4.0.3, 10.5.1.0, 10.5.2.0 and 10.6.0.0  
  • Sentry versions 9.7.2 and earlier, and 9.8.0;  
  • Monitor and Reporting Database (RDB) version 2.0.0.1 and earlier
CVE-2020-1631
  • Junos OS 12.3, 12.3X48, 14.1X53, 15.1, 15.1X49, 15.1X53, 17.2, 17.3, 17.4, 18.1, 18.2, 18.3, 18.4, 19.1, 19.2, 19.3, 19.4, 20.1
CVE-2020-2021
  • PAN-OS 9.1 versions earlier than PAN-OS 9.1.3; PAN-OS 9.0 versions earlier than PAN-OS 9.0.9; PAN-OS 8.1 versions earlier than PAN-OS 8.1.15, and all versions of PAN-OS 8.0 (EOL)
CVE-2020-1472
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1
  • Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation)
  • Windows Server 2012
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2016
  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows Server, version 1903  (Server Core installation)
  • Windows Server, version 1909  (Server Core installation)
  • Windows Server, version 2004   (Server Core installation)
Comprehensive Account Resets

If there is an observation of CVE-2020-1472 Netlogon activity or other indications of valid credential abuse detected, it should be assumed the APT actors have compromised AD administrative accounts, the AD forest should not be fully trusted, and, therefore, a new forest should be deployed. Existing hosts from the old compromised forest cannot be migrated in without being rebuilt and rejoined to the new domain, but migration may be done through “creative destruction,” wherein as endpoints in the legacy forest are decommissioned, new ones can be built in the new forest. This will need to be completed on on-premise as well as Azure hosted AD instances.

Note that fully resetting an AD forest is difficult and complex; it is best done with the assistance of personnel who have successfully completed the task previously.

It is critical to perform a full password reset on all user and computer accounts in the AD forest. Use the following steps as a guide.

  1. Create a temporary administrator account, and use this account only for all administrative actions
  2. Reset the Kerberos Ticket Granting Ticket (krbtgt) password; this must be completed before any additional actions and a second reset will take place in step 5
  3. Wait for the krbtgt reset to propagate to all domain controllers (time may vary)
  4. Reset all account passwords (passwords should be 15 characters or more and randomly assigned):
    1. User accounts (forced reset with no legacy password reuse)
    2. Local accounts on hosts (including local accounts not covered by Local Administrator Password Solution [LAPS])
    3. Service accounts
    4. Directory Services Restore Mode (DSRM) account
    5. Domain Controller machine account
    6. Application passwords
  5. Reset the krbtgt password again
  6. Wait for the krbtgt reset to propagate to all domain controllers (time may vary)
  7. Reboot domain controllers
  8. Reboot all endpoints

The following accounts should be reset:

  • AD Kerberos Authentication Master (2x)
  • All Active Directory Accounts
  • All Active Directory Admin Accounts
  • All Active Directory Service Accounts
  • All Active Directory User Accounts
  • DSRM Account on Domain Controllers
  • Non-AD Privileged Application Accounts
  • Non-AD Unprivileged Application Accounts
  • Non-Windows Privileged Accounts
  • Non-Windows User Accounts
  • Windows Computer Accounts
  • Windows Local Admin
VPN Vulnerabilities

Implement the following recommendations to secure your organization’s VPNs:

  • Update VPNs, network infrastructure devices, and devices being used to remote into work environments with the latest software patches and security configurations. See CISA Tips Understanding Patches and Securing Network Infrastructure Devices. Wherever possible, enable automatic updates. See table 1 for patch information on VPN-related CVEs mentioned in this report.
  • Implement multi-factor authentication (MFA) on all VPN connections to increase security. Physical security tokens are the most secure form of MFA, followed by authenticator app-based MFA. SMS and email-based MFA should only be used when no other forms are available. If MFA is not implemented, require teleworkers to use strong passwords. See CISA Tips Choosing and Protecting Passwords and Supplementing Passwords for more information.

Discontinue unused VPN servers. Reduce your organization’s attack surface by discontinuing unused VPN servers, which may act as a point of entry for attackers. How to protect your organization against VPN vulnerabilities:

  • Audit configuration and patch management programs.
  • Monitor network traffic for unexpected and unapproved protocols, especially outbound to the internet (e.g., SSH, SMB, RDP).
  • Implement MFA, especially for privileged accounts.
  • Use separate administrative accounts on separate administration workstations.
  • Keep software up to date. Enable automatic updates, if available.  

To secure your organization’s Netlogon channel connections:

  • Update all Domain Controllers and Read Only Domain Controllers. On August 11, 2020, Microsoft released software updates to mitigate CVE-2020-1472. Applying this update to domain controllers is currently the only mitigation to this vulnerability (aside from removing affected domain controllers from the network).
  • Monitor for new events, and address non-compliant devices that are using vulnerable Netlogon secure channel connections.
  • Block public access to potentially vulnerable ports, such as 445 (SMB) and 135 (RPC).

To protect your organization against this CVE, follow advice from Microsoft, including:

  • Update your domain controllers with an update released August 11, 2020 or later.
  • Find which devices are making vulnerable connections by monitoring event logs.
  • Address non-compliant devices making vulnerable connections.
  • Enable enforcement mode to address CVE-2020-1472 in your environment.
How to uncover and mitigate malicious activity
  • Collect and remove for further analysis:
    • Relevant artifacts, logs, and data
  • Implement mitigation steps that avoid tipping off the adversary that their presence in the network has been discovered.
  • Consider soliciting incident response support from a third-party IT security organization to:
    • Provide subject matter expertise and technical support to the incident response,
    • Ensure that the actor is eradicated from the network, and
    • Avoid residual issues that could result in follow-up compromises once the incident is closed
Resources 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
  • October 9, 2020: Initial Version

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QNAP Releases Security Updates for QNAP Helpdesk

US-Cert Current Activity - Thu, 10/08/2020 - 4:10pm
Original release date: October 8, 2020

QNAP Systems has released security updates to address vulnerabilities in QNAP Helpdesk. An attacker could exploit these vulnerabilities to take control of an affected QNAP network-attached storage (NAS) device.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review QNAP Security Advisory QSA-20-08 and apply the necessary updates.

This product is provided subject to this Notification and this Privacy & Use policy.

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Cisco Releases Security Updates

US-Cert Current Activity - Thu, 10/08/2020 - 11:19am
Original release date: October 8, 2020

Cisco has released security updates to address vulnerabilities in Cisco products. An attacker could exploit some of these vulnerabilities to take control of an affected system. For updates addressing lower severity vulnerabilities see the Cisco Security Advisories page.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review the following Cisco Advisories and apply the necessary updates:

This product is provided subject to this Notification and this Privacy & Use policy.

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Google Releases Security Updates for Chrome

US-Cert Current Activity - Wed, 10/07/2020 - 11:42am
Original release date: October 7, 2020

Google has released Chrome version 86.0.4240.75 for Windows, Mac, and Linux. This version addresses vulnerabilities that an attacker could exploit to take control of an affected system.

The Cybersecurity and Infrastructure Security Agency (CISA) encourages users and administrators to review the Chrome Release and apply the necessary changes.
 

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AA20-280A: Emotet Malware

US-Cert Alerts - Tue, 10/06/2020 - 1:00pm
Original release date: October 6, 2020
Summary

This Alert uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework. See the ATT&CK for Enterprise framework for all referenced threat actor techniques.

This product was written by the Cybersecurity and Infrastructure Security Agency (CISA) and the Multi-State Information Sharing & Analysis Center (MS-ISAC).

Emotet—a sophisticated Trojan commonly functioning as a downloader or dropper of other malware—resurged in July 2020, after a dormant period that began in February. Since August, CISA and MS-ISAC have seen a significant increase in malicious cyber actors targeting state and local governments with Emotet phishing emails. This increase has rendered Emotet one of the most prevalent ongoing threats.

To secure against Emotet, CISA and MS-ISAC recommend implementing the mitigation measures described in this Alert, which include applying protocols that block suspicious attachments, using antivirus software, and blocking suspicious IPs.

Technical Details

Emotet is an advanced Trojan primarily spread via phishing email attachments and links that, once clicked, launch the payload (Phishing: Spearphishing Attachment [T1566.001], Phishing: Spearphishing Link [T1566.002]).The malware then attempts to proliferate within a network by brute forcing user credentials and writing to shared drives (Brute Force: Password Guessing [T1110.001], Valid Accounts: Local Accounts [T1078.003], Remote Services: SMB/Windows Admin Shares [T1021.002]).

Emotet is difficult to combat because of its “worm-like” features that enable network-wide infections. Additionally, Emotet uses modular Dynamic Link Libraries to continuously evolve and update its capabilities.

Since July 2020, CISA has seen increased activity involving Emotet-associated indicators. During that time, CISA’s EINSTEIN Intrusion Detection System, which protects federal, civilian executive branch networks, has detected roughly 16,000 alerts related to Emotet activity. CISA observed Emotet being executed in phases during possible targeted campaigns. Emotet used compromised Word documents (.doc) attached to phishing emails as initial insertion vectors. Possible command and control network traffic involved HTTP POST requests to Uniform Resource Identifiers consisting of nonsensical random length alphabetical directories to known Emotet-related domains or IPs with the following user agent string (Application Layer Protocol: Web Protocols [T1071.001]).

Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; .NET4.0E; InfoPath.3; .NET CLR

Traffic to known Emotet-related domains or IPs occurred most commonly over ports 80, 8080, and 443. In one instance, traffic from an Emotet-related IP attempted to connect to a suspected compromised site over port 445, possibly indicating the use of Server Message Block exploitation frameworks along with Emotet (Exploitation of Remote Services [T1210]). Figure 1 lays out Emotet’s use of enterprise techniques.

 

Figure 1: MITRE ATT&CK enterprise techniques used by Emotet

  Timeline of Activity

The following timeline identifies key Emotet activity observed in 2020.

  • February: Cybercriminals targeted non-U.S. countries using COVID-19-themed phishing emails to lure victims to download Emotet.[1]
  • July: Researchers spotted emails with previously used Emotet URLs, particularly those used in the February campaign, targeting U.S. businesses with COVID-19-themed lures.[2]
  • August:
    • Security researchers observed a 1,000 percent increase in downloads of the Emotet loader. Following this change, antivirus software firms adjusted their detection heuristics to compensate, leading to decreases in observed loader downloads.[3]  
    • Proofpoint researchers noted mostly minimal changes in most tactics and tools previously used with Emotet. Significant changes included:
      • Emotet delivering Qbot affiliate partner01 as the primary payload and
      • The Emotet mail sending module’s ability to deliver benign and malicious attachments.[4]
    • CISA and MS-ISAC observed increased attacks in the United States, particularly cyber actors using Emotet to target state and local governments.
  • September:
    • Cyber agencies and researchers alerted the public of surges of Emotet, including compromises in Canada, France, Japan, New Zealand, Italy, and the Netherlands. Emotet botnets were observed dropping Trickbot to deliver ransomware payloads against some victims and Qakbot Trojans to steal banking credentials and data from other targets.[5],[6],[7],[8]
    • Security researchers from Microsoft identified a pivot in tactics from the Emotet campaign. The new tactics include attaching password-protected archive files (e.g., Zip files) to emails to bypass email security gateways. These email messages purport to deliver documents created on mobile devices to lure targeted users into enabling macros to “view” the documents—an action which actually enables the delivery of malware.[9]
    • Palo Alto Networks reported cyber actors using thread hijacking to spread Emotet. This attack technique involves stealing an existing email chain from an infected host to reply to the chain—using a spoofed identity—and attaching a malicious document to trick recipients into opening the file.[10]
MITRE ATT&CK Techniques

According to MITRE, Emotet uses the ATT&CK techniques listed in table 1.

Table 1: Common exploit tools

Technique

Use

OS Credential Dumping: LSASS Memory [T1003.001]

Emotet has been observed dropping password grabber modules including Mimikatz.

Remote Services: SMB/Windows Admin Shares [T1021.002]

Emotet leverages the Admin$ share for lateral movement once the local admin password has been brute forced.

Obfuscated Files or Information [T1027]

Emotet has obfuscated macros within malicious documents to hide the URLs hosting the malware, cmd.exe arguments, and PowerShell scripts.

Obfuscated Files or Information: Software Packing [T1027.002]

Emotet has used custom packers to protect its payloads.

Network Sniffing [T1040]

Emotet has been observed to hook network APIs to monitor network traffic.

Exfiltration Over C2 Channel [T1041]

Emotet has been seen exfiltrating system information stored within cookies sent within a HTTP GET request back to its command and control (C2) servers.

Windows Management Instrumentation [T1047]

Emotet has used WMI to execute powershell.exe.

Process Injection: Dynamic-link Library Injection [T1055.001]

Emotet has been observed injecting in to Explorer.exe and other processes.

Process Discovery [T1057]

Emotet has been observed enumerating local processes.

Command and Scripting Interpreter: PowerShell [T1059.001]

Emotet has used Powershell to retrieve the malicious payload and download additional resources like Mimikatz.

Command and Scripting Interpreter: Windows Command Shell [T1059.003]

Emotet has used cmd.exe to run a PowerShell script.

Command and Scripting Interpreter: Visual Basic [T1059.005]

Emotet has sent Microsoft Word documents with embedded macros that will invoke scripts to download additional payloads.

Valid Accounts: Local Accounts [T1078.003]

Emotet can brute force a local admin password, then use it to facilitate lateral movement.

Account Discovery: Email Account [T1087.003]

Emotet has been observed leveraging a module that can scrape email addresses from Outlook.

Brute Force: Password Guessing [T1110.001]

Emotet has been observed using a hard-coded list of passwords to brute force user accounts.

Email Collection: Local Email Collection [T1114.001]

Emotet has been observed leveraging a module that scrapes email data from Outlook.

User Execution: Malicious Link [T1204.001]

Emotet has relied upon users clicking on a malicious link delivered through spearphishing.

User Execution: Malicious File [T1204.002]

Emotet has relied upon users clicking on a malicious attachment delivered through spearphishing.

Exploitation of Remote Services [T1210]

Emotet has been seen exploiting SMB via a vulnerability exploit like ETERNALBLUE (MS17-010) to achieve lateral movement and propagation.

Create or Modify System Process: Windows Service [T1543.003]

Emotet has been observed creating new services to maintain persistence.

Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder [T1547.001]

Emotet has been observed adding the downloaded payload to the HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run key to maintain persistence.

Scheduled Task/Job: Scheduled Task [T1053.005]

Emotet has maintained persistence through a scheduled task.

Unsecured Credentials: Credentials In Files [T1552.001]

Emotet has been observed leveraging a module that retrieves passwords stored on a system for the current logged-on user.

Credentials from Password Stores: Credentials from Web Browsers [T1555.003]

Emotet has been observed dropping browser password grabber modules.

Archive Collected Data [T1560]

Emotet has been observed encrypting the data it collects before sending it to the C2 server.

Phishing: Spearphishing Attachment [T1566.001]

Emotet has been delivered by phishing emails containing attachments.

Phishing: Spearphishing Link [T1566.002]

Emotet has been delivered by phishing emails containing links.

Non-Standard Port [T1571]

Emotet has used HTTP over ports such as 20, 22, 7080, and 50000, in addition to using ports commonly associated with HTTP/Hypertext Transfer Protocol Secure.

Encrypted Channel: Asymmetric Cryptography [T1573.002]

Emotet is known to use RSA keys for encrypting C2 traffic.

Detection Signatures

MS-ISAC developed the following Snort signature for use in detecting network activity associated with Emotet activity.

alert tcp $HOME_NET any -> $EXTERNAL_NET 443 (msg:"[CIS] Emotet C2 Traffic Using Form Data to Send Passwords"; content:"POST"; http_method; content:"Content-Type|3a 20|multipart/form-data|3b 20|boundary="; http_header; fast_pattern; content:"Content-Disposition|3a 20|form-data|3b 20|name=|22|"; http_client_body; content:!"------WebKitFormBoundary"; http_client_body; content:!"Cookie|3a|"; pcre:"/:?(chrome|firefox|safari|opera|ie|edge) passwords/i"; reference:url,cofense.com/flash-bulletin-emotet-epoch-1-changes-c2-communication/; sid:1; rev:2;)

CISA developed the following Snort signatures for use in detecting network activity associated with Emotet activity. Note: Uniform Resource Identifiers should contain a random length alphabetical multiple directory string, and activity will likely be over ports 80, 8080, or 443.

alert tcp any any -> any $HTTP_PORTS (msg:"EMOTET:HTTP URI GET contains '/wp-content/###/'"; sid:00000000; rev:1; flow:established,to_server; content:"/wp-content/"; http_uri; content:"/"; http_uri; distance:0; within:4; content:"GET"; nocase; http_method; urilen:<17; classtype:http-uri; content:"Connection|3a 20|Keep-Alive|0d 0a|"; http_header; metadata:service http;)

alert tcp any any -> any $HTTP_PORTS (msg:"EMOTET:HTTP URI GET contains '/wp-admin/###/'"; sid:00000000; rev:1; flow:established,to_server; content:"/wp-admin/"; http_uri; content:"/"; http_uri; distance:0; within:4; content:"GET"; nocase; http_method; urilen:<15; content:"Connection|3a 20|Keep-Alive|0d 0a|"; http_header; classtype:http-uri; metadata:service http;)

Mitigations

CISA and MS-ISAC recommend that network defenders—in federal, state, local, tribal, territorial governments, and the private sector—consider applying the following best practices to strengthen the security posture of their organization's systems. System owners and administrators should review any configuration changes prior to implementation to avoid unwanted impacts.

  • Block email attachments commonly associated with malware (e.g.,.dll and .exe).
  • Block email attachments that cannot be scanned by antivirus software (e.g., .zip files).
  • Implement Group Policy Object and firewall rules.
  • Implement an antivirus program and a formalized patch management process.
  • Implement filters at the email gateway, and block suspicious IP addresses at the firewall.
  • Adhere to the principle of least privilege.
  • Implement a Domain-Based Message Authentication, Reporting & Conformance validation system.
  • Segment and segregate networks and functions.
  • Limit unnecessary lateral communications.
  • Disable file and printer sharing services. If these services are required, use strong passwords or Active Directory authentication.
  • Enforce multi-factor authentication.
  • Exercise caution when opening email attachments, even if the attachment is expected and the sender appears to be known. See Using Caution with Email Attachments.
  • Enable a firewall on agency workstations, configured 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 suspicious or risky sites.
  • Exercise caution when using removable media (e.g., USB thumb drives, external drives, CDs).
  • Scan all software downloaded from the internet prior to executing.
  • Maintain situational awareness of the latest threats and implement appropriate access control lists.
  • Visit the MITRE ATT&CK Techniques pages (linked in table 1 above) for additional mitigation and detection strategies.
  • See CISA’s Alert on Technical Approaches to Uncovering and Remediating Malicious Activity for more information on addressing potential incidents and applying best practice incident response procedures.
  • See the joint CISA and MS-ISAC Ransomware Guide on how to be proactive and prevent ransomware attacks from happening and for a detailed approach on how to respond to an attack and best resolve the cyber incident.

For additional information on malware incident prevention and handling, see the National Institute of Standards and Technology Special Publication 800-83, Guide to Malware Incident Prevention and Handling for Desktops and Laptops.

Resources References Revisions
  • October 6, 2020: Initial Version

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Categories: US-CERT Feed

CISA Releases FY2019 Risk Vulnerability Assessment Infographic

US-Cert Current Activity - Tue, 10/06/2020 - 9:13am
Original release date: October 6, 2020

The Cybersecurity and Information Security Agency (CISA) has released an infographic mapping analysis of 44 of its Risk and Vulnerability Assessments (RVAs) conducted in Fiscal Year 2019 to the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK) Framework. The infographic identifies routinely successful attack paths CISA observed during RVAs conducted across multiple sectors. Cyber attackers can use these attack paths to compromise organizations.

CISA encourages network administrators and IT professionals to review the infographic and apply the recommended defensive strategies to protect against the observed tactics and techniques. Review CISA’s Cyber Essentials for more information on where to start implementing organizational cybersecurity practices. For information on CISA RVAs and requesting additional services, visit CISA’s National Cybersecurity Assessment and Technical Services page.  

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Categories: US-CERT Feed

Department of Treasury Releases Advisory on Potential Sanctions Risks for Facilitating Ransomware Payments

US-Cert Current Activity - Fri, 10/02/2020 - 11:09am
Original release date: October 2, 2020

The U.S. Department of the Treasury’s Office of Foreign Assets Control (OFAC) has released an [Advisory on Potential Sanctions Risks for Facilitating Ransomware Payments]. Financial institutions, cyber insurance firms, and companies that facilitate payments on behalf of victims may be violating OFAC regulations.

CISA encourages organizations to review the OFAC Advisory for more information. See CISA’s Ransomware page for how to report and protect against ransomware attacks.

This product is provided subject to this Notification and this Privacy & Use policy.

Categories: US-CERT Feed

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