Analysis by: Maureen Reyes

ALIASES:

Win32/Emotet.BH (ESET-NOD32), Trojan.Win32.Agent.qwgsyv (Kaspersky), Win32.Trojan-Spy.Emotet.QS (GData)

 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 deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size: 221,184 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 25 May 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 - file is dropped here if it has admin privileges
  • %AppDataLocal%\Microsoft\Windows\{Random filename}.exe - file is dropped here if it has no admin privileges

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Autostart Technique

This Trojan Spy 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\{Random filename}
ImagePath = "%system%\{Random filename}.exe" -{Random number} -{Random number}

It adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ctxmdmaus = '%AppDataLocal%\Microsoft\Windows\{Random filename}.exe"

It starts the following services:

  • {Random filename}

Other Details

This Trojan Spy connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.91.235
  • http://{BLOCKED}.{BLOCKED}.124.163
  • http://{BLOCKED}.{BLOCKED}.30.202
  • http://{BLOCKED}.{BLOCKED}.135.76
  • http://{BLOCKED}.{BLOCKED}.84.2
  • http://{BLOCKED}.{BLOCKED}.129.4
  • http://{BLOCKED}.{BLOCKED}.26.179
  • http://{BLOCKED}.{BLOCKED}.81.235

It deletes the initially executed copy of itself

NOTES:

This malware creates a startup service if it has admin privileges, otherwise it creates an auto-run registry.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.274.08
FIRST VSAPI PATTERN DATE: 25 May 2018
VSAPI OPR PATTERN File: 14.275.00
VSAPI OPR PATTERN Date: 26 May 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 ]
    • {Random filename}

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.

  • In HKEY_LOCAL_MACHINE\System\CurrentControlSet\services
    • {Random filename}

Step 6

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%\Microsoft\Windows\{Random filename}.exe"

Step 7

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