Analysis by: John Anthony Banes

ALIASES:

HEUR:Trojan-Proxy.Win32.Glupteba.gen (Kaspersky); a variant of Win32/Glupteba.BC trojan (NOD32)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

This Backdoor 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 commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.

It gathers information and reports it to its servers.

  TECHNICAL DETAILS

File Size: 683,008 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 27 Jun 2018
Payload: Connects to URLs/IPs, Compromises system security, Collects system information

Arrival Details

This Backdoor 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 Backdoor drops the following copies of itself into the affected system and executes them:

  • %Application Data%\EpicNet Inc\CloudNet\cloudnet.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.)

It creates the following folders:

  • %Application Data%\EpicNet Inc\CloudNet

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

  • Global\Mp6c3Ygukx29GbDk
  • Global\fd6c128733fc1d31f48a431ee6dfe1bc

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
CloudNet = %Application Data%\Roaming\EpicNet Inc\CloudNet\cloudnet.exe

Other System Modifications

This Backdoor adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CloudNet

HKEY_CURRENT_USER\Software\EpicNet Inc.

HKEY_CURRENT_USER\Software\EpicNet Inc.\
CloudNet

It adds the following registry entries:

HKEY_CURRENT_USER\Software\EpicNet Inc.\
CloudNet
Value = {date}

HKEY_CURRENT_USER\Software\EpicNet Inc.\
CloudNet
GUID = {GUID}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CloudNet
DisplayName = CloudNet

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CloudNet
DisplayVersion = 20170301

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CloudNet
Publisher = EpicNet Inc.

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CloudNet
InstallLocation = %Application Data%\EpicNet Inc\CloudNet

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CloudNet
DisplayIcon = %Application Data%\EpicNet Inc\CloudNet\cloudnet.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
CloudNet
UninstallString = %Application Data%\EpicNet Inc\CloudNet\cloudnet.exe /uninstall

Backdoor Routine

This Backdoor executes the following commands from a remote malicious user:

  • Creates a proxy connection
  • Gather information from past created proxy connection
  • Close socket of proxy connection
  • Modify its added registry entries value and svalue
  • Download and execute arbitrary file

It connects to the following websites to send and receive information:

  • {GUID}.server-{1 to 40}.photoadvice.online
  • {GUID}.server-{1 to 40}.photoadvice.pw
  • {GUID}.server-{1 to 40}.0ek.ru
  • {GUID}.server-{1 to 40}.0vu.ru

Other Details

This Backdoor connects to the following URL(s) to check for an Internet connection:

  • www.google.com

It does the following:

  • Because this backdoor is capable of creating proxy connections, it is able to use the infected computer and may serve as a relay to spam emails or redirect to advertisement networks.
  • This backdoor notifies the URLs mentioned above by sending the following HTTP GET request, and then receives a port number, to which the backdoor will connect to:
    • /stat?uid={value}&downlink={value}&uplink={value}&id={value}&statpass={value}&version={value}&features={value}&guid={value}&comment={value}&p={value}&s={value}
  • It deletes and uninstalls itself if the "/uninstall" argument is present, or if the user uninstalls it manually using "Add or Remove Programs" setting.
  • It terminates itself if the following registry key and entry is not present in the affected system:
    • HKEY_CURRENT_USER\Software\Microsoft\TestApp
    • UUID = {value}

It gathers the following information and reports it to its servers:

  • Malware Version
  • Operating System Version
  • If User is Admin
  • Malware C&Cs
  • Processor Name
  • GPU Name
  • Memory (RAM)

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 14.350.02
FIRST VSAPI PATTERN DATE: 30 Jun 2018
VSAPI OPR PATTERN File: 14.351.00
VSAPI OPR PATTERN Date: 01 Jul 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

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\EpicNet Inc.\CloudNet
    • Value = {date}
  • In HKEY_CURRENT_USER\Software\EpicNet Inc.\CloudNet
    • GUID = {GUID}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CloudNet
    • DisplayName = CloudNet
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CloudNet
    • DisplayVersion = 20170301
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CloudNet
    • Publisher = EpicNet Inc.
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CloudNet
    • InstallLocation = %Application Data%\EpicNet Inc\CloudNet
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CloudNet
    • DisplayIcon = %Application Data%\EpicNet Inc\CloudNet\cloudnet.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Uninstall\CloudNet
    • UninstallString = %Application Data%\EpicNet Inc\CloudNet\cloudnet.exe /uninstall

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\Microsoft\Windows\CurrentVersion\Uninstall
    • CloudNet
  • In HKEY_CURRENT_USER\Software\EpicNet Inc.
    • CloudNet
  • In HKEY_CURRENT_USER\Software
    • EpicNet Inc.

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.
  • %Application Data%\EpicNet Inc\CloudNet

Step 7

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