Analysis by: Melvin Jhun Palbusa
ALIASES:

UDS:Backdoor.Win64.Wineloader.a (KASPERSKY)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Type: EXE
Memory Resident: No
Initial Samples Received Date: 04 Apr 2024
Payload: Connects to URLs/IPs

Arrival Details

This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Backdoor Routine

This Backdoor executes the following commands from a remote malicious user:

  • Execute modules from the C2 either synchronously or asynchronously (via CreateThread)
  • Inject itself into another DLL
  • Update the sleep interval between beacon requests

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

  • https://{BLOCKED}htools.com/api.php

Other Details

This Backdoor does the following:

  • It injects itself twice to a randomly selected DLL from Windows System directory except the following DLL:
    • advapi32.dll
    • api-ms-win-crt-math-l1-1-0.dll
    • api-ms-win-crt-stdio-l1-1-0.dll
    • bcryptprimitives.dll
    • iphlpapi.dll
    • kernel32.dll
    • kernelbase.dll
    • mscoree.dll
    • ntdll.dll
    • ole32.dll
    • rpcrt4.dll
    • shlwapi.dll
    • user32.dll
    • wininet.dll

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 19.258.05
FIRST VSAPI PATTERN DATE: 04 Apr 2024
VSAPI OPR PATTERN File: 19.259.00
VSAPI OPR PATTERN Date: 05 Apr 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

Scan your computer with your Trend Micro product to delete files detected as Backdoor.Win64.WINELOADER.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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