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TROJ_EMOTET.WJSP

February 11, 2016
 Analysis by: Rhena Inocencio
 ALIASES:

Trojan:Win32/Emotet (Microsoft), Win32/Emotet.AB (ESET)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


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

However, as of this writing, the said sites are inaccessible. It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

163,840 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

13 Nov 2014

Arrival Details

This Trojan 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 drops the following files:

  • %Application Data%\ms{random number}.bat
    This is used to delete the initial malware copy. This file is deleted afterwards

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

It drops the following copies of itself into the affected system:

  • %Application Data%\Identities\{random filename}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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 adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random filename}.exe = "%Application Data%\Identities\{random filename}.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Local AppWizard-Generated Applications\
LPR_location

HKEY_CURRENT_USER\Software\Netscape\
5.0\{random number}\{character}{random number}

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}.61.98:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.3.6:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.2.225:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.59.84:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.69.28:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.238.80:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.73.156:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.86.196:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.233.170:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.167.213:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.50.238:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.44.120:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.168.224:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.31.56:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.127.2:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.56.124:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.62.76:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.162.65:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.213.230:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.18.97:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.130.225:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.101.155:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.40.249:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.11.121:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.216.199:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.19.234:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.184.219:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.219.82:8080/{random value 1}/{random value 2}/
  • http://{BLOCKED}.{BLOCKED}.11.156:8080/{random value 1}/{random value 2}/

However, as of this writing, the said sites are inaccessible.

It deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

11.274.03

FIRST VSAPI PATTERN DATE:

13 Nov 2014

VSAPI OPR PATTERN File:

11.2745.00

VSAPI OPR PATTERN Date:

14 Nov 2014

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

Scan your computer with your Trend Micro product and note files detected as TROJ_EMOTET.WJSP

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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}.exe = "%Application Data%\Identities\{random filename}.exe"

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_CURRENT_USER\Software\Local AppWizard-Generated Applications
    • LPR_location

Step 6

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

Step 7

The following created files/folders/registry keys/registry entries cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present system information with a backup. Note that the said components do not have to be deleted since it won't be harmful to the system.

  • In HKEY_CURRENT_USER\Software\Netscape\5.0\{random number}
    • {character}{random number}


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