Analysis by: Cris Nowell Pantanilla
ALIASES:

Trojan:Win32/Emotet.K (Microsoft), Trojan-Banker.Win32.Emotet.vkn (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Trojan may be dropped by other malware.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size: 162,304 bytes
Memory Resident: Yes
Initial Samples Received Date: 19 Apr 2017
Payload: Connects to URLs/IPs, Steals information

Arrival Details

This Trojan may be dropped by the following malware:

  • JS_EMOTET

Installation

This Trojan drops the following copies of itself into the affected system:

  • %Application Data%\{random name}\{random name}.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 drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

  • %User Startup%\{random name}.lnk

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)

Download Routine

This Trojan accesses the following websites to download files:

  • {BLOCKED}.{BLOCKED}.166.45:8080
  • {BLOCKED}.{BLOCKED}.136.67:443
  • {BLOCKED}.{BLOCKED}.218.25:443
  • {BLOCKED}.{BLOCKED}.137.34:7080
  • {BLOCKED}.{BLOCKED}.254.64:8080
  • {BLOCKED}.{BLOCKED}.220.214:8080
  • {BLOCKED}.{BLOCKED}.221.180:7080
  • {BLOCKED}.{BLOCKED}.27.246:8080
  • {BLOCKED}.{BLOCKED}.246.7:8080
  • {BLOCKED}.{BLOCKED}.220.79:8080

It saves the files it downloads using the following names:

  • %User Temp%\{random filename}.tmp

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

Information Theft

This Trojan attempts to steal stored email credentials from the following:

  • Installed mail clients

Other Details

This Trojan does the following:

  • It uses a combination for the following strings for its filename (ex. InstancingGlossary.exe):
    • Alaska
    • Another
    • Appid
    • Assessment
    • Auth
    • Bold
    • Brush
    • Character
    • Cpl
    • Createan
    • Dfs
    • Dhcp
    • Disabled
    • Dsui
    • Enclosure
    • Executor
    • Fltr
    • Fluid
    • Generalize
    • Glossary
    • Grammar
    • Group
    • Hash
    • Header
    • Ifra
    • Instancing
    • Isvc
    • Itha
    • Key
    • Kor
    • Lang
    • Latn
    • License
    • Msmq
    • Mspthrd
    • Multimedia
    • Natural
    • Npapi
    • Otp
    • Overview
    • Params
    • Pdl
    • Playingona
    • Programs
    • Quota
    • Reason
    • Scroll
    • Secret
    • Simple
    • Sms
    • Source
    • Step
    • Teal
    • Tsd
    • Users
    • Vdm
    • Volume
    • Vsip
    • Wake
    • Wallpaper
    • Webcam
    • Workflow
    • Xian
    • Zone

It deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.350.04
FIRST VSAPI PATTERN DATE: 19 Apr 2017
VSAPI OPR PATTERN File: 13.351.00
VSAPI OPR PATTERN Date: 20 Apr 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

[ Learn More ]

Step 4

Remove the malware/grayware file dropped/downloaded by TROJ_EMOTET.XXTB. (Note: Please skip this step if the threat(s) listed below have already been removed.)

     
    • JS_EMOTET.GQA

Step 5

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %User Startup%\{random name}.lnk

Step 6

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