Trojan.PS1.POWLOAD.TIAOENT

 Analysis by: Charles Adrian Marty

 ALIASES:

Trojan-Banker.Win32.Emotet.btip (MICROSOFT)

 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

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

614,048 bytes

File Type:

ZIP

Memory Resident:

No

Initial Samples Received Date:

28 Mar 2023

Payload:

Connects to URLs/IPs, Downloads files, Enables macros, Drops 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.

Installation

This Trojan drops the following files:

  • %User Temp%\{8 random characters}.{3 random characters}.ps1 -> deleted afterwards
  • %User Temp%\{8 random characters}.{3 random characters}.psm1 -> deleted afterwards

(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 {Encrypted commands} do set Bcd=!Bcd!!rl:~%X,1!&&if %X lss 4 echo !Bcd:~5! |FOR /F "delims=dZ\s tokens=10" %n IN ('ftype^^^|find "sole."')DO %n -"
  • %System%\cmd.exe {Encrypted commands} do set Bcd=!Bcd!!rl:~%X,1!&&if %X lss 4 echo !Bcd:~5! |FOR /F "delims=dZ\s tokens=10" %n IN ('ftype^^^|find "sole."')DO %n -"
  • %System%\cmd.exe {Encrypted commands used to connect and download executable file}
  • %System%\cmd.exe /S /D /c" FOR /F "delims=dZ\s tokens=10" %n IN ('ftype^|find "sole."') DO %n -"
  • %System%\cmd.exe /c ftype|find"sole."
  • %System%\cmd.exe /S /D /C" ftype"
  • %System%\find.exe find "sole."
  • %System%\WindowsPowerShell\v1.\powershell.exe PowerShell -

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Download Routine

This Trojan downloads the file from the following URL and renames the file when stored in the affected system:

  • http://{BLOCKED}d.com/p
  • http://{BLOCKED}ngsuk.com/Kv
  • http://{BLOCKED}z.net/WSS
  • http://{BLOCKED}h.com/kNLSCHYq
  • http://{BLOCKED}oarquitetura.com.br/pqFhOq

It saves the files it downloads using the following names:

  • %User Temp%\618.exe -> deleted afterwards

(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).)

As of this writing, the said sites are inaccessible.

Other Details

This Trojan does the following:

  • The document contains the following message details luring users to enable macro content:

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.362.04

FIRST VSAPI PATTERN DATE:

04 Apr 2023

VSAPI OPR PATTERN File:

18.363.00

VSAPI OPR PATTERN Date:

05 Apr 2023

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

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%\{8 random characters}.{3 random characters}.ps1
  • %User Temp%\{8 random characters}.{3 random characters}.psm1
  • %User Temp%\618.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.PS1.POWLOAD.TIAOENT. 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:

Step 5

Enable the macro virus protection in Microsoft Office Applications

[ Learn More ]


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