TSPY_EMOTET.THABOCAH

December 05, 2018
 Analysis by: Maureen Reyes
 ALIASES:

Trojan-Banker.Win32.Emotet.bsso (Kaspersky), Trojan-Banker.Emotet (Ikarus)

 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

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.

It executes then deletes itself afterward.

  TECHNICAL DETAILS

File Size:

429,568 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

30 Nov 2018

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 copies of itself into the affected system and executes them:

  • %System%\{Random Filename}.exe - > dropped when file is run with admin rights
  • %AppDataLocal%\{Random Name}\{Random Filename}.exe -> dropped when file is run without admin rights

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista, 7, and 8.)

It executes then deletes itself afterward.

Autostart Technique

This Trojan Spy adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Random File Name} = "%AppDataLocal%\{Random Name}\{Random Filename}.exe"

It starts the following services:

  • Service Name: {Random Filename}
    Description:Maintains an updated list of computers on the network and supplies this list to computers designated as browsers. If this service is stopped, this list will not be updated or maintained. If this service is disabled, any service that explicitly depends on it will fail to start.
    Image Path: "%System%\{Random Filename}.exe"

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

Other Details

This Trojan Spy connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.203.165
  • {BLOCKED}.{BLOCKED}.126.78
  • {BLOCKED}.{BLOCKED}.106.8
  • {BLOCKED}.{BLOCKED}.22.169

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.664.04

FIRST VSAPI PATTERN DATE:

03 Dec 2018

VSAPI OPR PATTERN File:

14.665.00

VSAPI OPR PATTERN Date:

04 Dec 2018

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

[ Learn More ]

Step 4

Disable this malware service

[ Learn More ]
    • Service Name: {Random Name}
    • Description: Maintains an updated list of computers on the network and supplies this list to computers designated as browsers. If this service is stopped, this list will not be updated or maintained. If this service is disabled, any services that explicitly depend on it will fail to start.
    • Image Path: "%System%\{Random Filename}.exe"

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\Windows\CurrentVersion\Run
    • {Random Filename} = "%AppDataLocal%\{Random Name}\{Random Filename}.exe"

Step 6

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