BKDR_LUMINOSITY.C

 Analysis by: Jeanne Jocson

 ALIASES:

Trojan:Win32/Skeeyah.A!rfn (Microsoft), Trojan.MSIL.Injector (Ikarus), MSIL/Injector.OUL (ESET), Trojan.MSIL.Smalo.jw (Kaspersky)

 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 does not have any propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system.

  TECHNICAL DETAILS

File Size:

11,776 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

11 Apr 2016

Payload:

Connects to URLs/IPs, Terminates processes

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%\WinRAR\nwtray.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 drops the following file(s)/component(s):

  • %Application Data%\WinRAR\nvvswc.exe(watchdog) - also detected as BKDR_LUMINOSITY.C

(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 processes:

  • svchost.exe
  • AppLaunch.exe
  • vbc.ex
  • RegAsm.exe
  • RegSvcs.exe

Autostart Technique

This backdoor modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = "%Application Data%\WinRAR\nvvswc.exe"

(Note: The default value data of the said registry entry is "".)

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

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

  • Downloads and executes arbitrary files
  • Downloads and executes custom Crypto Miner
  • Downloads custom password recovery tool
  • Searches for files
  • Performs DDOS
  • Modifies HOSTS file to redirect hosts/URLs
  • Visits arbitrary websites (browser can be hidden and have muted audio)
  • Seeds torrent
  • Updates itself
  • Updates backup C&C
  • Remotes Desktop Control
  • Remotes shell
  • Remotes Script
  • Records audio using system's microphone
  • Controls Webcam
  • Uninstalls itself
  • Executes/Terminates/Disables Task Manager
  • Executes/Terminates/Disables Command Prompt
  • Executes/Terminates/Disables Registry Editor
  • Hides/Shows Taskbar
  • Hides/Shows Desktop
  • Opens/Closes CD-ROM door
  • Turns on/off user's monitor
  • Enables/Disables Keyboard
  • Enables/Disables Mouse
  • Swaps/Resets Mouse
  • Deletes Restore points
  • Enables/Disables input
  • Logs off User
  • Hibernates
  • Shutdowns system
  • Reboots System
  • Performs network speed test
  • Manage Files
  • Manage Processes
  • Gathers the following information:
    • Client Overview:
      • Client ID used
      • Country
    • Software Information:
      • User Privelege
      • Machine Name
    • Hardware Information:
      • Machine Type
      • CPU Information
      • GPU Information
      • RAM Information
      • Battery
      • Monitor Count
    • Network Information:
      • WAN address
      • Download Speed
      • LAN Address
      • MAC Address
    • Others:
      • Security information
      • Uptime
      • Active Windows
      • Current malware file location
      • Full OS version
      • Keystroke logs
      • Stored passwords

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • kelelumi77.{BLOCKED}s.net:6318

NOTES:

This malware is capable of proactively blocks anti-malware services by querying the installed anti-malware/firewall product in the system. Once an anti-malware/firewall is found, it terminates the corresponding anti-malware service/process.

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine:

9.8

FIRST VSAPI PATTERN FILE:

12.460.05

FIRST VSAPI PATTERN DATE:

11 Apr 2016

VSAPI OPR PATTERN File:

12.461.00

VSAPI OPR PATTERN Date:

12 Apr 2016

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

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator’s help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
    • From: Load = "%Application Data%\WinRAR\nvvswc.exe"
      To: Load = ""

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_LUMINOSITY.C. 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 6

Scan your computer with your Trend Micro product to delete files detected as BKDR_LUMINOSITY.C. 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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