Analysis by: Maureen Reyes
ALIASES:

Trojan.Emotet (Symantec), Trojan-Banker.Win32.Emotet.ccex (Kaspersky)

 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.

  TECHNICAL DETAILS

File Size: 227,328 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 28 Jan 2019

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:

  • %AppDataLocal%\devslide\{Random Filename}.exe -> without admin rights
  • %System%\{Random Filename}.exe - > with admin rights

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

It creates the following folders:

  • %AppDataLocal%\devslide

(Note: %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.)

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 Filename} = "%AppDataLocal%\devslide\{Random Filename}.exe"

It starts the following services:

  • Service Name: {Random Filename}
    Description: BDESVC hosts the BitLocker Drive Encryption service. BitLocker Drive Encryption provides secure startup for the operating system, as well as full volume encryption for OS, fixed or removable volumes. This service allows BitLocker to prompt users for various actions related to their volumes when mounted, and unlocks volumes automatically without user interaction. Additionally, it stores recovery information to Active Directory, if available, and, if necessary, ensures the most recent recovery certificates are used. Stopping or disabling the service would prevent users from leveraging this functionality.
    ImagePath: "%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:

  • http://{BLOCKED}.{BLOCKED}.20.198:995/
  • http://{BLOCKED}.{BLOCKED}.37.237:20/

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.778.05
FIRST VSAPI PATTERN DATE: 28 Jan 2019
VSAPI OPR PATTERN File: 14.779.00
VSAPI OPR PATTERN Date: 29 Jan 2019

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 Filename}
    • Description: BDESVC hosts the BitLocker Drive Encryption service. BitLocker Drive Encryption provides secure startup for the operating system, as well as full volume encryption for OS, fixed or removable volumes. This service allows BitLocker to prompt users for various actions related to their volumes when mounted, and unlocks volumes automatically without user interaction. Additionally, it stores recovery information to Active Directory, if available, and, if necessary, ensures the most recent recovery certificates are used. Stopping or disabling the service would prevent users from leveraging this functionality.
    • ImagePath: "%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%\devslide\{Random Filename}.exe"

Step 6

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.
  • %AppDataLocal%\devslide

Step 7

Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.Win32.EMOTET.THOABHAI. 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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