Analysis by: Elton Rondero

ALIASES:

Trojan-Banker.Win32.Emotet.dbii(KASPERSKY); Trojan:Win32/Emotet.AD!bit(MICROSOFT)

 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

Infection Channel: Downloaded from the Internet, Dropped by other malware

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.

It connects to a website to send and receive information.

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

  TECHNICAL DETAILS

File Size: 209,208 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 30 Apr 2019
Payload: Connects to URLs/IPs, Steals information

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:

  • If sample executed with administrative privileges:
    • %System%\{String1}{String2}.exe
  • If sample executed without administrative privileges:
    • %AppDataLocal%\{String1}{String2}\{String1}{String2}.exe

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following processes:

  • {Malware file path}\{Malware file name}.exe --{8 Random Characters}
  • If sample executed with administrative privileges:
    • %System%\{String1}{String2}.exe
    • %System%\{String1}{String2}.exe --{8 Random Characters}
  • If sample executed without administrative privileges:
    • %AppDataLocal%\{String1}{String2}\{String1}{String2}.exe
    • %AppDataLocal%\{String1}{String2}\{String1}{String2}.exe --{8 Random Characters}

(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It creates the following folders:

  • If the sample is executed without administrative privileges:
    • %AppDataLocal%\{String1}{String2}

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It executes then deletes itself afterward.

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • Global\I{Volume Serial Number}
  • Global\M{Volume Serial Number}

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\{String1}{String2}
ImagePath = %System%\{String1}{String2}.exe

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

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{String1}{String2} = %AppDataLocal%\{String1}{String2}\{String1}{String2}.exe

Backdoor Routine

This Trojan Spy connects to the following websites to send and receive information:

  • {BLOCKED}.{BLOCKED}.252.27:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.252.249:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.254.93:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.117.247:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.212.42:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.67.226:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.203.51:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.160.193:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.35.103:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.45.129:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.131.215:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.142.40:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.148.222:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.200.27:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.86.72:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.143.100:7080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.50.164:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.93.123:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.206.153:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.248.48:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.215.57:7080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.1.74:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.79.48:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.163:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.112.70:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.185.71:465/{Random Characters}
  • {BLOCKED}.{BLOCKED}.213.173:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.62.186:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.33.82:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.6.78:7080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.90.90:7080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.69.165:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.85.35:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.105.16:465/{Random Characters}
  • {BLOCKED}.{BLOCKED}.199.254:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.94.183:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.52.242:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.252.27:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.252.249:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.254.93:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.117.247:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.212.42:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.67.226:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.203.51:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.160.193:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.35.103:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.45.129:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.131.215:443/{Random Characters}
  • {BLOCKED}.{BLOCKED}.142.40:8080/{Random Characters}
  • {BLOCKED}.{BLOCKED}.148.222:8080/{Random Characters}

Information Theft

This Trojan Spy gathers the following data:

  • Computer Name
  • Process SessionId
  • OS Version
  • Running Processes
  • File CRC
  • Processor Architecture

Other Details

This Trojan Spy does the following:

  • It creates the service for persistence if the sample is executed with administrative privileges, otherwise it uses an autorun registry.
  • It combines any two of the following strings and uses it as its filename "{String1}{String2}":
    • rel
    • tables
    • glue
    • impl
    • texture
    • related
    • key
    • nis
    • langs
    • iprop
    • exec
    • wrap
    • matrix
    • dump
    • phoenix
    • ribbon
    • sorting
    • pinned
    • lics
    • bit
    • unpack
    • adt
    • rep
    • jobs
    • acl
    • title
    • sound
    • events
    • targets
    • scrn
    • mheg
    • lines
    • prompt
    • adjust
    • xian
    • ser
    • cycle
    • redist
    • its
    • boxes
    • dma
    • small
    • cloud
    • flow
    • guiddef
    • whole
    • parent
    • bears
    • random
    • bulk
    • idebug
    • viewer
    • starta
    • comment
    • sel
    • source
    • hotspot
    • pnf
    • portal
    • sitka
    • iell
    • slide
    • typ
    • sonic
  • It deletes outdated copies of itself with a combination of any two of the following strings as its file name:
    • not
    • ripple
    • svcs
    • serv
    • wab
    • shader
    • single
    • without
    • wcs
    • define
    • eap
    • culture
    • slide
    • zip
    • tmpl
    • mini
    • polic
    • panes
    • earcon
    • menus
    • detect
    • form
    • uuidgen
    • pnp
    • admin
    • tuip
    • avatar
    • started
    • dasmrc
    • alaska
    • guids
    • wfp
    • adam
    • wgx
    • lime
    • indexer
    • repl
    • dev
    • mapi
    • resw
    • daf
    • diag
    • iss
    • vsc
    • turned
    • neutral
    • sat
    • source
    • enroll
    • mfidl
    • idl
    • based
    • right
    • cbs
    • radar
    • avg
    • wordpad
    • metagen
    • mouse
    • iprop
    • mdmmcd
    • jersey
    • thunk
    • subs

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

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.970.05
FIRST VSAPI PATTERN DATE: 30 Apr 2019
VSAPI OPR PATTERN File: 14.971.00
VSAPI OPR PATTERN Date: 01 May 2019

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • Troj.Win32.TRX.XXPE50FFF030

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

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 4

Identify and terminate files detected as TrojanSpy.Win32.EMOTET.THDCOAI

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

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
    • {String1}{String2} = %AppDataLocal%\{String1}{String2}\{String1}{String2}.exe

Step 6

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
    • {String1}{String2}

Step 7

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.
  • %System%\{String1}{String2}.exe
  • %AppDataLocal%\{String1}{String2}\{String1}{String2}.exe

Step 8

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