Trojan.Win32.MIRAI.MJY

 Analysis by: Noel Anthony Llimos

 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


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.

  TECHNICAL DETAILS

File Size:

5,632 bytes

File Type:

DLL

Memory Resident:

No

Initial Samples Received Date:

04 May 2018

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.

Download Routine

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

  • http://208.{BLOCKED}.{BLOCKED}.150/v1.rar
  • http://66.{BLOCKED}.{BLOCKED}.174/ups.rar
  • http://www.cy{BLOCKED16.{BLOCKEDz:8888/clr.txt

It saves the files it downloads using the following names:

  • clr.txt → Contains the URL that will download additional malicious files.
  • %Windows%\system\cabs.exe → detected as Backdoor.Win32.MIRAI.MJY
  • %Temp%\v.exe → detected as Trojan.Win32.DISKWRITE.AA

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

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.772.06

FIRST VSAPI PATTERN DATE:

25 Jan 2019

VSAPI OPR PATTERN File:

14.773.00

VSAPI OPR PATTERN Date:

26 Jan 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

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.
  • clr.txt → Contains the URL that will download additional malicious files.
  • %Windows%\system\cabs.exe
  • %Temp%\v.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.MIRAI.MJY. 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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