Auteur Sujet: [FireEye]TRITON Actor TTP Profile, Custom Attack Tools, Detections, and ATT&CK Mapping  (Lu 157 fois)

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TRITON Actor TTP Profile, Custom Attack Tools, Detections, and
ATT&CK Mapping


Overview


 

FireEye can now confirm that we have uncovered and are responding
    to an additional intrusion by the attacker behind TRITON at a
    different critical infrastructure facility
.


 

In December 2017, FireEye publicly released our first analysis on
  the     href="https://www.fireeye.com/blog/threat-research/2017/12/attackers-deploy-new-ics-attack-framework-triton.html">TRITON
  attack where malicious actors used the TRITON custom attack
  framework to manipulate industrial safety systems at a critical
  infrastructure facility and inadvertently caused a process shutdown.
  In subsequent   href="https://www.fireeye.com/blog/threat-research/2018/06/totally-tubular-treatise-on-triton-and-tristation.html">research
  we examined how the attackers may have gained access to critical
  components needed to build the TRITON attack framework. In our most
  recent   href="https://www.fireeye.com/blog/threat-research/2018/10/triton-attribution-russian-government-owned-lab-most-likely-built-tools.html">analysis,
  we attributed the intrusion activity that led to the deployment of
  TRITON to a Russian government-owned technical research institute in Moscow.


 

The TRITON intrusion is shrouded in mystery. There has been some
  public discussion surrounding the TRITON framework and its impact at
  the target site, yet little to no information has been shared on the
  tactics, techniques, and procedures (TTPs) related to the intrusion
  lifecycle, or how the attack made it deep enough to impact the
  industrial processes. The TRITON framework itself and the intrusion
  tools the actor used were built and deployed by humans, all of whom
  had observable human strategies, preferences, and conventions for the
  custom tooling of the intrusion operation. It is our goal to discuss
  these adversary methods and highlight exactly how the developer(s),
  operator(s) and others involved used custom tools in the intrusion.


 

In this report we continue our research of the actor’s operations
  with a specific focus on a selection of custom information technology
  (IT) tools and tactics the threat actor leveraged during the early
  stages of the targeted attack lifecycle (Figure 1). The information in
  this report is derived from multiple TRITON-related incident responses
  carried out by FireEye Mandiant.


 

Using the methodologies described in this post, FireEye Mandiant
  incident responders have uncovered additional intrusion activity from
  this threat actor – including new custom tool sets – at a second
  critical infrastructure facility. As such, we strongly encourage
  industrial control system (ICS) asset owners to leverage the
  indicators, TTPs, and detections included in this post to improve
  their defenses and hunt for related activity in their networks.


 

For IT and operational technology (OT) incident response support,
  please contact FireEye
  Mandiant
. For more in-depth analysis of TRITON and other cyber
  threats, consider subscribing to     href="https://www.fireeye.com/solutions/cyber-threat-intelligence.html?utm_source=google&utm_medium=cpc&utm_content=paid-search&gclid=CjwKCAjwstfkBRBoEiwADTmnEF8VtsXQ9TPcLxWWJqMm6EnpG2o5dsmJqK282QEZCDkw_sMQSB-YOhoCKkIQAvD_BwE&gclsrc=aw.ds">FireEye
    Cyber Threat Intelligence.


 

FireEye’s   href="https://www.fireeye.com/company/press-releases/2018/fireeye-unveils-smartvision-edition-to-detect-stealthy--maliciou.html">SmartVision
  technology, which searches for attackers during lateral movement
  activities by monitoring east-west traffic in IT and OT networks,
  reduces the risk of an attack reaching sensitive ICS processes. This
  is particularly relevant for sophisticated ICS-related intrusions as
  attackers typically move from corporate IT to OT networks through
  systems that are accessible to both environments, far beyond perimeter defenses.


 

Contents


 
  • Tools and TTPs

  •    
  • Hunting for ICS-focused threat actors across IT and OT

  •    
  • Methodology and discovery strategies
  • Appendix A:
        Discovery Rules
  • Appendix B: Technical Analysis of Custom
        Attack Tools
  • Appendix C: MITRE ATT&CK JSON Raw
      Data
  • Indicators of Compromise

 


 
 
 Figure 1: The FireEye targeted attack lifecycle


 

Actor Leveraged a Variety of Custom and Commodity Intrusion Tools


 

Throughout the targeted attack lifecycle, the actor leveraged dozens
  of custom and commodity intrusion tools to gain and maintain access to
  the target's IT and OT networks. A selection of the custom tools that
  FireEye Mandiant recovered are listed later in this post in Table 1,
  and hashes are listed in Table 2 at the end of this post. Discovery
  rules for and technical analysis of these tools, as well as MITRE
  ATT&CK JSON raw data, is available in Appendix A, Appendix B, and
  Appendix C.


 


 
 
 Figure 2: Selection of custom tools used
    by the actor


 

The actor's custom tools frequently mirrored the functionality of
  commodity tools and appear to be developed with a focus on anti-virus
  evasion. The group often leveraged custom tools when they appeared to
  be struggling with anti-virus detection or were at a critical phase in
  the intrusion (e.g., they switched to custom backdoors in IT and OT
  DMZ right before gaining access to the engineering workstation). In
  some instances, the actor leveraged custom and commodity tools for the
  same function. For example, they used Mimikatz (public) and SecHack
  (custom) for credential harvesting; both tools provide a very similar
  output (Figure 2).


 


 
 
 Figure 3: Default outputs for Mimikatz
    (left) and SecHack (right)


 

Tools and TTPs Indicate a Deep Interest in Ensuring Prolonged and
  Persistent Access to the Target Environment


 

The targeted attack lifecycle of a sophisticated ICS attack is often
  measured in years. Attackers require a long time to prepare for such
  an attack in order to learn about the target’s industrial processes
  and build custom tools. These attacks are also often carried out by
  nation states that may be interested in preparing for contingency
  operations rather than conducting an immediate attack (e.g.,
  installing malware like TRITON and waiting for the right time to use
  it). During this time, the attacker must ensure continued access to
  the target environment or risk losing years of effort and potentially
  expensive custom ICS malware. This attack was no exception. The actor
  was present in the target networks for almost a year before gaining
  access to the Safety Instrumented System (SIS) engineering
  workstation. Throughout that period, they appeared to prioritize
  operational security.


 

After establishing an initial foothold on the corporate network, the
  TRITON actor focused most of their effort on gaining access to the OT
  network. They did not exhibit activities commonly associated with
  espionage, such as using key loggers and screenshot grabbers, browsing
  files, and/or exfiltrating large amounts of information. Most of the
  attack tools they used were focused on network reconnaissance, lateral
  movement, and maintaining presence in the target environment.


 

The actor used multiple techniques to hide their activities, cover
  their tracks, and deter forensic examination of their tools and activities.


 
  • They renamed their files
        to make them look like legitimate files, for example,
        KB77846376.exe, named after Microsoft update files.
  • They
        routinely used standard tools that would mimic legitimate
        administrator activities. This included heavy use of RDP and
      PsExec/WinRM.
  • When planting webshells on the Outlook Exchange
        servers, they modified already existing legitimate flogon.js and
        logoff.aspx files.
  • They relied on encrypted SSH-based
        tunnels to transfer tools and for remote command/program
      execution.
  • They used multiple staging folders and opted to
        use directories that were used infrequently by legitimate users or
      processes.
  • They routinely deleted dropped attack tools,
        execution logs, files staged for exfiltration, and other files after
        they were finished with them.
  • They renamed their tools'
        filenames in the staging folder so that it would not be possible to
        identify the malware's purpose, even after it was deleted from the
        disk through the residual artifacts (e.g., ShimCache entries or WMI
        Recently Used Apps).
  • They used timestomping to modify the
        $STANDARD_INFORMATION attribute of the attack tools.

 

Once the actor gained access to the targeted SIS controllers, they
  appeared to focus solely on maintaining access while attempting to
  successfully deploy TRITON. This involved strategically limiting their
  activities to mitigate the risk of being discovered.


 
  • The actor gained a
        foothold on the distributed control system (DCS) but did not
        leverage that access to learn about plant operations, exfiltrate
        sensitive information, tamper with the DCS controllers, or
        manipulate the process.
  • They then gained access to an SIS
        engineering workstation. From this point forward, they focused most
        of their effort on delivering and refining a backdoor payload using
        the TRITON attack framework.
  • They attempted to reduce the
        chance of being observed during higher-risk activities by
        interacting with target controllers during off-hour times. This
        would ensure fewer workers were on site to react to potential alarms
        caused by controller manipulation.
  • They renamed their files
        to make them look like legitimate files, for example, trilog.exe,
        named after a legitimate Schneider Electric application.

 

Operational Since At Least 2014


 

Based on analysis of the actor’s custom intrusion tools, the group
  has been operating since as early as 2014. It is worth noting that
  FireEye had never before encountered any of the actor's custom tools,
  despite the fact that many of them date to several years before the
  initial compromise. This fact and the actor's demonstrated interest in
  operational security suggests there may be other target environments –
  beyond the second intrusion announced in this blog post – where the
  actor was or still is present.


 
  • A sample of a
        Cryptcat-based backdoor used to establish the initial foothold was
        recovered during the investigation; the sample was compiled and
        uploaded to a malware testing environment by the actor in 2014.

  •    
  • Cryptcat- and PLINK-based backdoors were scheduled to execute
        daily starting from April 28, 2014, using ProgramDataUpdater and
        NetworkAccessProtectionUpdateDB tasks. This date is unrelated to the
        observed intrusion timeline and may indicate the date the threat
        actors first created these persistence mechanisms.

  •    
  • NetExec.exe, a custom lateral movement and remote command
        execution tool, is self-titled "NetExec 2014 by OSA."

  •    
  • SecHack.exe "by OSA," a custom credential harvesting
        and reconnaissance tool, was compiled on Oct. 23, 2014.
  • The
        attackers used a pirated version of Wii.exe, a public file indexing
        tool that came with a license from 2010 and has not been updated
        since 2014.

 

ICS Asset Owners Should Prioritize Detection and Defense Across
  Windows Systems in Both IT and OT


 

Most sophisticated ICS attacks leveraged Windows, Linux, and other
  traditionally "IT" systems (located in either IT or OT
  networks) as a conduit to the ultimate target. Some examples include
  leveraging computers to gain access to targeted PLCs (e.g., Stuxnet),
  interacting directly with internet-connected human machine interfaces
  (HMIs) (e.g., BlackEnergy), and gaining remote access to an
  engineering station to manipulate a remote terminal unit (RTU) (e.g.,
  INDUSTROYER) or infect SIS programmable logic controllers (PLC) (e.g., TRITON).


 

Defenders who focus on stopping an attacker in these
  "conduit" systems benefit from a number of key advantages.
  These advantages will only grow as IT and OT systems continue to converge.


 
  • Attackers commonly leave
        a broad footprint in IT systems across most if not all the attack
      lifecycle.
  • It is ideal to stop an attacker as early in the
        attack lifecycle as possible (aka "left of boom"). Once an
        attacker reaches the targeted ICS, the potential of a negative
        outcome and its severity for the target increase dramatically.

  •    
  • There are many mature security tools, services, and other
        capabilities already available that can be leveraged to defend and
        hunt in "conduit" systems.

 

Leveraging Known Tools and TTPs To Hunt For the TRITON Actor


 

Historic activity associated with this actor demonstrates a strong
  development capability for custom tooling. The developer(s) behind
  these toolsets leaned heavily on existing software frameworks and
  modified them to best serve the intrusion operations. The developer(s)
  had preferences regarding the ports, protocols, persistence
  mechanisms, and other aspects of how the malware operated.


 

While the preferences of the development team supporting this
  activity will likely shift and change over time, learning about them
  is still useful to identify whether their TTPs are applicable to other
  malware developers and threat actors. Additionally, the actor possibly
  gained a foothold on other target networks—beyond the two intrusions
  discussed in this post – using similar strategies. In such cases,
  retrospective hunting would help defenders identify and remediate
  malicious activity.


 

Based on the examination of developer(s) preferences and abstracted
  adversary methodologies, it is possible to build broader visibility of
  the TTPs using detection and hunting rules of various fidelity and
  threat density. The compilation of these rules makes it possible to
  identify and classify potentially malicious samples while building new
  "haystacks" in which to hunt for adversary activity.


 

The TTPs we extracted from this actor’s activities are not
  necessarily exclusive, nor are they necessarily malicious in every
  circumstance. However, the TTP profile built by FireEye can be used to
  search for patterns of evil in subsets of network and endpoint
  activity. Not only can these TTPs be used to find evidence of
  intrusions, but identification of activity that has strong overlaps
  with the actor's favored techniques can lead to stronger assessments
  of actor association, further bolstering incident response efforts.


 

The following table provides insights into notable methodologies
  surrounding the use of custom tools and tips for identifying evidence
  of this and related activity. Adversary methodologies are also
  expressed in terms of the MITRE ATT&CK framework (see Appendix C
  for MITRE ATT&CK JSON raw data).


 
   
     
   
     
   
     
   
     
   
     
   
     
   
                width="0">

Look for newly observed 2LD and 3LD domains that
          contain hyphens.


   
     
   
     
   
     
   
     
       
   
     
   
     
   
     
   
     
   
     
   
                width="0">

Look for PEs with Bitvise PDB path strings such
          as d:\repos\main\ssh2\.


   
                width="0">

Look for PEs with content "Microsoft openSSH
        client."


   
     
   
     
   
     
       
   
     
       
   
     


         
            Adversary Methodology


         
            Discovery Tips

Persistence by Scheduled Tasks by XML trigger


                      href="https://attack.mitre.org/techniques/T1053/">ATT&CK:
        T1053

Look for new and anomalous
                        href="https://docs.microsoft.com/en-us/windows/desktop/taskschd/daily-trigger-example--xml-">Scheduled
            Tasks XML triggers referencing unsigned .exe files.


     

Persistence by IFEO injection


                      href="https://attack.mitre.org/techniques/T1183/">ATT&CK:
        T1183

Look for modifications and
          new entries referencing .exe files under registry key
          HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
          NT\CurrentVersion\Image File Execution Options.

Command and control (C2) established using
          hard-coded DNS servers

Look for PEs
          executions with run DNS lookups to 8.8.8.8:53. This may be
          applicable to sandbox and other malware processing
        technologies.

C2 using favored C2ports


                      href="https://attack.mitre.org/techniques/T1043/">ATT&CK:
        T1043


                      href="https://attack.mitre.org/techniques/T1065/">ATT&CK:
        T1065

Look for outbound
          connections with port-protocol mismatches on common and
          uncommon ports such as 443, 4444, 8531, and 50501.

C2 using favored Virtual Private Server (VPS)
        infrastructure


                      href="https://attack.mitre.org/techniques/T1329/">ATT&CK:
        T1329

Look for inbound and
          outbound connections from and to non-standard IP ranges,
          especially from international VPS providers like OVH and UK-2
          Limited (uk2.net).

C2 domains with hyphen

C&C using dynamic DNS domains from
        afraid.org


                      href="https://attack.mitre.org/techniques/T1311/">ATT&CK:
        T1311

Look for newly observed
          dynamic DNS domains owned or registered with afraid.org.


     

C2 domains registered with vfemail.net email
        addresses

Look for newly observed
          domains or DNS resolutions to domains with registrant email
          information containing vfemail.net

Tunneled RDP using PLINK


                      href="https://attack.mitre.org/techniques/T1076/">ATT&CK:
        T1076

Look for the presence of
          PLINK and non-standard RDP usage with event logs, firewall
          logs, and registry keys as described in the FireEye blog post
            "            href="https://www.fireeye.com/blog/threat-research/2019/01/bypassing-network-restrictions-through-rdp-tunneling.html">Bypassing
            Network Restrictions Through RDP Tunneling."


         

Find internal RDP pivoting by looking for bitmap cache
          files under user accounts that should not be accessing
          sensitive systems via RDP. Look for bitmap cache files such as
          bcache22.bmc under default, service, or administrator accounts
          or any account not expected to be conducting internal RDP
          accesses to sensitive systems in a protected OT-connected
          zone, especially in the DMZ or DCS areas like HMIs or
          engineering workstations.

C2 using hard-coded SSH private keys

Look for PEs with hard-coded OpenSSH private
        keys.

Use of direct RDP


                      href="https://attack.mitre.org/techniques/T1076/">ATT&CK:
        T1076

Look for inbound RDP
          connections with default host information, non-standard or
          unexpected locale IDs, or other metadata. See also the             href="https://www.fireeye.com/blog/threat-research/2018/04/establishing-a-baseline-for-remote-desktop-protocol.html">FireEye
            blog post on baselining RDP activity.

C2 using source systems with default Windows
        hostnames

Look for default Windows
          hostnames that fit the structure WIN-[A-Z0-9]{11} (e.g.,
          WIN-ABCDEFGH1JK) in PE certificates, SSL and SSH certificates,
          and RDP handshakes.

C2 using SSH

Look for
          new, unique, or unusual SSH sessions. Logging of SSH keys and
          fingerprints would quickly and easily identify an anomalous
          session as a result of malware. Look for SSH over non-standard
        ports.

Compromised VPN accounts


                      href="https://attack.mitre.org/techniques/T1078/">ATT&CK:
        T1078

Look for VPN logon
          anomalies based on infeasible patterns such as source account
          location, IP address, and hostname associations. Check out the
          FireEye blog post and free toolset for VPN logon analysis,         href="https://www.fireeye.com/blog/threat-research/2018/05/remote-authentication-geofeasibility-tool-geologonalyzer.html">GeoLogonalyzer.


         

If you use SMS-based MFA, look for phone numbers registered
          outside the country where your employees operate.

Malware masquerading as Microsoft Corporation


     

Look for PEs with mismatched PE metadata
          such as contains "Bitvise" strings and also
          "Microsoft Corporation" in the metadata. Look for
          unsigned "Microsoft Corporation" binaries in the
          group's common staging directories.

Use of customized Bitvise binaries

Use of customized OpenSSH binaries

Use of customized Cryptcat but with default
        password

Look for PEs that drop
          Cryptcat binaries or contain Cryptcat string content such as
          the default password "metallica."

Timestomping via PowerShell


                      href="https://attack.mitre.org/techniques/T1099/">ATT&CK:
        T1099

Look for timestomping
          command strings such as ".CreationTime=" in
          PowerShell scripts or in PowerShell command-line entries. Look
          for PEs with NTFS creation time prior to PE compile time.


     

Deployment of binaries with debug information
          from developer workstations with Visual Studio 2010

Look for PEs with PDB paths containing default
          or generic paths such as

          style="list-style-position: inside;">
           
  • \Users\user\Documents\Visual Studio 2010\

  •            
  • \Documents\Visual Studio 2010\.
  • Use of Thinstall for packaging malware

    Look for PE with content
              "thinstall\modules\boot_loader.pdb." Look for
              Thinstall binaries that have created virtualized files in the
              context of the SYSTEM user
            "C:\Windows\SysWOW64\config\systemprofile\AppData\Roaming\Thinstall\."


         

    Use of favored directories for operating, staging
              and executing files

    Look for new,
              unexpected, or otherwise anomalous binaries in the following
            directories:


               
    • C:\Windows\system32\inetsrv\

    •          
    • C:\Windows\temp\
    • C:\Windows\SysWOW64\wbem

    •          
    • C:\Windows\SysWOW64\drivers

    •          
    • C:\Windows\SysWOW64

    •          
    • C:\Windows\system32\wbem\

    •          
    • C:\Windows\system32\drivers\

    •          
    • C:\Windows\system32\
    • C:\Windows\

    •          
    • C:\Users\Public\Libraries\

    •          
    • C:\Users\administrator\appdata\local\temp\

    •          
    • C:\ssh\
    • C:\perflogs\admin\servermanager\ssh\

    •          
    • C:\perflogs\admin\servermanager\

    •          
    • C:\perflogs\admin\
    • C:\perflogs\

    •          
    • C:\cpqsystem\
    • C:\hp\hpdiags\

    •          
    • C:\hp\bin\log\

     


      Table 1: TRITON actor methodology and discovery strategies


     

    Outlook


     

    There is often a singular focus from the security community on ICS
      malware largely due to its novel nature and the fact that there are
      very few examples found in the wild. While this attention is useful
      for a variety of reasons, we argue that defenders and incident
      responders should focus more attention on so-called
      "conduit" systems when trying to identify or stop
      ICS-focused intrusions.


     

    In an attempt to raise community awareness surrounding this actor’s
      capabilities and activities between 2014 and 2017—an effort compounded
      in importance by our discovery of the threat actor in a second
      critical infrastructure facility—we have shared a sampling of what we
      know about the group's TTPs and custom tooling. We encourage ICS asset
      owners to leverage the detection rules and other information included
      in this report to hunt for related activity as we believe there is a
      good chance the threat actor was or is present in other target networks.


     

    For IT and OT incident response support, please contact     href="https://www.fireeye.com/services.html">FireEye Mandiant.
      For more in-depth analysis of TRITON and other cyber threats, consider
      subscribing to     href="https://www.fireeye.com/solutions/cyber-threat-intelligence.html?utm_source=google&utm_medium=cpc&utm_content=paid-search&gclid=CjwKCAjwstfkBRBoEiwADTmnEF8VtsXQ9TPcLxWWJqMm6EnpG2o5dsmJqK282QEZCDkw_sMQSB-YOhoCKkIQAvD_BwE&gclsrc=aw.ds">FireEye
        Cyber Threat Intelligence.


     

    FireEye’s   href="https://www.fireeye.com/company/press-releases/2018/fireeye-unveils-smartvision-edition-to-detect-stealthy--maliciou.html">SmartVision
      technology, which searches for attackers during lateral movement
      activities by monitoring east-west traffic in IT and OT networks,
      reduces the risk of an attack reaching sensitive ICS processes. This
      is particularly relevant for sophisticated ICS-related intrusions as
      attackers typically move from corporate IT to OT networks through
      systems that were accessible to both environments, far beyond
      perimeter defenses.


     

    Appendices


     

    •           href="https://www.fireeye.com/content/dam/fireeye-www/blog/pdfs/TRITON_Appendix_A.pdf">Appendix
            A: Discovery Rules

    •           href="https://www.fireeye.com/content/dam/fireeye-www/blog/pdfs/TRITON_Appendix_B.pdf">Appendix
            B: Technical Analysis of Custom Attack Tools

    •           href="https://www.fireeye.com/content/dam/fireeye-www/blog/pdfs/TRITON_Appendix_C.pdf">Appendix
            C: MITRE ATT&CK JSON Raw Data

    Source: TRITON Actor TTP Profile, Custom Attack Tools, Detections, and
    ATT&CK Mapping

    Security-X


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