Analysis by: Wilbert Vidal
 PLATFORM:

Windows

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 115,200 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 01 Dec 2017

Arrival Details

This Spyware 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 Spyware drops and executes the following files:

  • %System%\{random alphanumeric characters}.exe
  • %System%\{filename 1}{filename 2}.exe

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

Autostart Technique

This Spyware registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\{filename 1}{filename 2}
ImagePath = %System%\{filename 1}{filename 2}.exe

Other Details

This Spyware connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.103.194
  • {BLOCKED}.{BLOCKED}.238.174

It deletes itself after execution.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.822.03
FIRST VSAPI PATTERN DATE: 04 Dec 2017
VSAPI OPR PATTERN File: 13.823.00
VSAPI OPR PATTERN Date: 05 Dec 2017

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 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

Restart in Safe Mode, and then 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.

 
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\{filename 1}{filename 2}
    • ImagePath = %System%\{filename 1}{filename 2}.exe

Step 4

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_EMOTET.YUYBAX. 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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