Analysis by: Paul Steven Nadera
ALIASES:

Trojan:Win32/Azorult.AA!MTB (Microsoft); a variant of Win32/Injector.ELOW trojan (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

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: 196,608 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 27 Apr 2020
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:

  • "{malware path}\{malware filename}"
  • "%System%\ntvdm.exe" -i1

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

Other System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
WARMFIKSTI\Affor1
EXCID = "Opkrve"

Download Routine

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

  • http://{BLOCKED}aewoi.ug/ds.exe

It saves the files it downloads using the following names:

  • %User Temp%\dds.exe

(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 adds the following registry keys:

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
WARMFIKSTI

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
WARMFIKSTI\Affor1

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.862.05
FIRST VSAPI PATTERN DATE: 11 May 2020
VSAPI OPR PATTERN File: 15.863.00
VSAPI OPR PATTERN Date: 12 May 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.XXPE50FFF035

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

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\VB and VBA Program Settings\WARMFIKSTI\Affor1
    • EXCID = "Opkrve"

Step 5

Delete this registry key

[ 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.

  • HKEY_CURRENT_USER\Software\VB and VBA Program Settings\WARMFIKSTI
  • HKEY_CURRENT_USER\Software\VB and VBA Program Settings\WARMFIKSTI\Affor1

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%\dds.exe

Step 7

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.DLOADR.TIOIBEHX. 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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