TrojanSpy.Win32.BOYCHI.A

 Analysis by: Raymart Christian Yambot

 ALIASES:

WORM/Boychi.hanub (ANTIVIR)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

This Trojan Spy 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.

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

  TECHNICAL DETAILS

File Size:

245,760 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

22 Apr 2024

Payload:

Collects system information, Connects to URLs/IPs, Drops files

Arrival Details

This Trojan Spy 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 Spy adds the following folders:

  • %AppDataLocal%\Microsoft\Outlooka\

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It drops the following files:

  • %AppDataLocal%\Microsoft\Outlooka\nlashine.ini
  • %AppDataLocal%\Microsoft\Outlooka\SysInfo_UP_22_16_11.pdf
  • %AppDataLocal%\Microsoft\Outlooka\UP{Driver Letter}

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • "cmd /c systeminfo >> %AppDataLocal%\MICROS~1\Outlooka\SysInfo_UP_22_16_11.pdf"
  • "powershell $dir = 'C:\Users\DYITUS~1\AppData\Local\MICROS~1\Outlooka\';$gps = @('A','B','C','D','E','F','G','H','I','H','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z');foreach ($gp in $gps){$drv = $gp + ':\';if([System.IO.Directory]::Exists($drv)){$path = $dir + '\UP' +$gp;tree /f "$drv" | Out-File -Encoding default-FilePath $path-Width 5000;} }
  • "%System%\tree.com" /f {Available Driver Letter}:\

Autostart Technique

This Trojan Spy drops the following file(s) in the Windows Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\rdpclipe.exe.lnk
  • %User Startup%\AWastUI.exe.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)

Download Routine

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

  • http://{BLOCKED}.{BLOCKED}.{BLOCKED}.48/ESOK/dwn.php?downfname=[(PC name)](user name)[IP address](random value}
  • http://{BLOCKED}.{BLOCKED}.{BLOCKED}.48/ESOK/del2.php?delfname=[(PC name)](usera name)[IP address](random value}

As of this writing, the said sites are inaccessible.

Information Theft

This Trojan Spy gathers the following data:

  • System information.
  • All file and folder names in every available drives.

Stolen Information

This Trojan Spy sends the gathered information via HTTP POST to the following URL:

  • http://{BLOCKED}.{BLOCKED}.{BLOCKED}.48/ESOK/post2.php

Other Details

This Trojan Spy does the following:

  • The malware attempts to establish a connection with a server using the GET command in order to verify its status.
    • http://{BLOCKED}.{BLOCKED}.{BLOCKED}.48/ESOK/up2.php

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

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

19.310.05

FIRST VSAPI PATTERN DATE:

30 Apr 2024

VSAPI OPR PATTERN File:

19.311.00

VSAPI OPR PATTERN Date:

01 May 2024

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • TROJ.Win32.TRX.XXPE50FFF079

Step 2

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 3

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 4

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.
  • %AppDataLocal%\Microsoft\Outlooka\nlashine.ini
  • %AppDataLocal%\Microsoft\Outlooka\SysInfo_UP_22_16_11.pdf
  • %AppDataLocal%\Microsoft\Outlooka\UP{Driver Letter}

Step 5

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %AppDataLocal%\Microsoft\Outlooka\

Step 6

Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.Win32.BOYCHI.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 the following Trend Micro Support pages for more information:


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