Analysis by: Julie Anne Cabuhat

 ALIASES:

Trojan.Mirai (Malwarebytes), Trojan.Mirai.1 (DrWeb)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW


This backdoor executes commands from a remote malicious user, effectively compromising the affected system. However, as of this writing, the said sites are inaccessible.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 3,501,008 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 14 Jan 2017
Payload: Connects to URLs/IPs, Compromises system security

Backdoor Routine

This backdoor executes the following commands from a remote malicious user:

  • Scan ports
  • Log computer information
  • Display console window
  • Start service
  • Stop service
  • Delete service
  • Create service
  • Run malware as application
  • Run malware as service

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • http://up.{BLOCKED}y.com:8888/

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

Download Routine

This backdoor accesses the following websites to download files:

  • http://up.{BLOCKED}y.com:8888/ver.txt
  • http://up.{BLOCKED}y.com:8888/ups.rar
  • http://up.{BLOCKED}y.com:8888/wpdmd5.txt

It connects to the following URL(s) to download its configuration file:

  • http://up.{BLOCKED}y.com:8888/wpd.dat

It saves the files it downloads using the following names:

  • %User Profile%\wpd.dat -> configuration file

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

As of this writing, the said sites are inaccessible.

Other Details

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

  • http://www.{BLOCKED}n.com/dyndns/getip

It does the following:

  • It attempts to stop and disable the following services:
    • Network List Service
    • Network Location Awareness

NOTES:

The backdoor needs the configuration file to properly run.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.210.04
FIRST VSAPI PATTERN DATE: 09 Feb 2017
VSAPI OPR PATTERN File: 13.211.00
VSAPI OPR PATTERN Date: 10 Feb 2017

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

Identify and terminate files detected as BKDR_MIRAI.A

[ 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 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 Profile%\wpd.dat

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_MIRAI.A. 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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