Analysis by: Clive Fuentebella
ALIASES:

Win32/Spy.Zbot.ADI trojan (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

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.

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

  TECHNICAL DETAILS

File Size: 229,580 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 14 Sep 2020
Payload: Connects to URLs/IPs

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 drops the following files:

  • %User Temp%\{Random numbers}
  • %User Temp%\ns{Random characters}.tmp\System.dll

(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:

  • {Malware file path and name}
  • msiexec.exe

It creates the following folders:

  • %User Temp%\ns{Random characters}.tmp

(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).)

Other System Modifications

This Trojan Spy adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
toxm
ugba = {Hex values}

HKEY_CURRENT_USER\Software\Microsoft\
{Random characters}
{Random characters} = {Hex values}

Backdoor Routine

This Trojan Spy connects to the following URL(s) to send and receive commands from a remote malicious user:

  • http://{BLOCKED}euetijabsnqsgn.com/LKhwojehDgwegSDG/gateJKjdsh.php
  • http://{BLOCKED}cgscbjlndewpxn.com/LKhwojehDgwegSDG/gateJKjdsh.php
  • http://{BLOCKED}yolrfeegaophef.com/LKhwojehDgwegSDG/gateJKjdsh.php
  • http://{BLOCKED}st2020.com/LKhwojehDgwegSDG/gateJKjdsh.php
  • http://{BLOCKED}st2020.in/LKhwojehDgwegSDG/gateJKjdsh.php
  • http://{BLOCKED}st2020.info/LKhwojehDgwegSDG/gateJKjdsh.php
  • http://{BLOCKED}st2020.net/LKhwojehDgwegSDG/gateJKjdsh.php
  • http://{BLOCKED}st2020.org/LKhwojehDgwegSDG/gateJKjdsh.php

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

Other Details

This Trojan Spy does the following:

  • It attempts to read the following files:
    • %Application Data%\{Random letters}\{Random letters}.{Random extension}
  • The information being stolen by the sample will depend on the response from the mentioned C&C servers.
  • If the connection failed on the mentioned C&C servers, it generates random URL(s) to connect onto.

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

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 16.216.06
FIRST VSAPI PATTERN DATE: 09 Sep 2020
VSAPI OPR PATTERN File: 16.217.00
VSAPI OPR PATTERN Date: 10 Sep 2020

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.XXPE50FSX002

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

Restart in Safe Mode

[ Learn More ]

Step 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\toxm
    • ugba={Hex values}
  • In HKEY_CURRENT_USER\Software\Microsoft\{Random characters}
    • {Random characters}={Hex values}

Step 6

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%\{Random numbers}
  • %User Temp%\ns{Random characters}.tmp\System.dll
  • %Application Data%\{Random letters}\{Random letters}.{Random extension}

Step 7

Search and delete these folders

[ 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.
  • %User Temp%\ns{Random characters}.tmp

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TrojanSpy.Win32.ZBOT.WLDX. 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 this Knowledge Base page for more information.


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