Analysis by: Rheniel Rhay Ramos
ALIASES:

Backdoor.Win32.Volgmer.d (Kaspersky); Backdoor:Win32/Joanap.I!dha (Microsoft); Trojan.Volgmer (Symantec)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

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 arrives as a component bundled with malware/grayware packages.

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

It gathers certain information on the affected computer.

  TECHNICAL DETAILS

File Size: 110,592 bytes
File Type: DLL
Memory Resident: No
Initial Samples Received Date: 31 Jan 2015
Payload: Connects to URLs/IPs, Steals information, Executes commands

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.

It arrives as a component bundled with malware/grayware packages.

Backdoor Routine

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

  • Gather System Information
  • Update Service Registry Keys -> used to change the encoded IP Adresses
  • Download and Upload Files
  • Execute Commands
  • Terminate Processes
  • List Directories

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

  • {BLOCKED}.{BLOCKED}.223.35/8080
  • {BLOCKED}.{BLOCKED}.244.194/8080
  • {BLOCKED}.{BLOCKED}.145.179/8080
  • {BLOCKED}.{BLOCKED}.9.20/8000
  • {BLOCKED}.{BLOCKED}.198.172/8080
  • {BLOCKED}.{BLOCKED}.71.97/8080
  • {BLOCKED}.{BLOCKED}.91.232/8088
  • {BLOCKED}.{BLOCKED}.97.148/8080
  • {BLOCKED}.{BLOCKED}.234.120/8080
  • {BLOCKED}.{BLOCKED}.69.133/8080
  • {BLOCKED}.{BLOCKED}.222.99/8080
  • {BLOCKED}.{BLOCKED}.87.181/8080
  • {BLOCKED}.{BLOCKED}.204.157/8088
  • {BLOCKED}.{BLOCKED}.224.218/8088
  • {BLOCKED}.{BLOCKED}.188.42/8080

Information Theft

This Backdoor gathers the following information on the affected computer:

  • Computer Name
  • Architecture and Type of Processor
  • Number of Processors
  • Volume Information
  • Locale Information
  • IP Address
  • TCP Connection State
  • Operating System Version
  • Process List

Other Details

This Backdoor does the following:

  • It queries the following registry keys and decodes their data which will contain the IP Adresses of the C&C Servers:
    • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\WMI\Security
      • 125463f3-2a9c-bdf0-d890-5a98b08d8898 = "{Hexadecimal Values}" -> encoded IP Adresses used as C&C
    • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\WMI\Security
      • f0012345-2a9c-bdf8-345d-345d67b542a1 = "{Hexadecimal Values}" -> encoded IP Adresses used as C&C
  • It will be run as a service with the following information by the malware that drops this file:
    • Service Name: "{Malware File Name}"
    • DisplayName: "{Random Combination}"
    • BinaryPathName: "%System%\svchost.exe -k LocalSystems"
    • Where {Random Combination} could be any 4 word combination of the following (i.e. "Control Intelligent User Profile Service"):
      • Application
      • Background
      • Control
      • Desktop
      • Extension
      • Function
      • Group
      • Host
      • Intelligent
      • Key
      • Layer
      • Multimedia
      • Network
      • Operation
      • Portable
      • Quality
      • Remote
      • Security
      • TCP/IP
      • User Profile
      • Volume
      • Windows
      • Device
      • Upd
      • Service
      • Management
      • Manager
      • Enum

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.786.07
FIRST VSAPI PATTERN DATE: 16 Nov 2017
VSAPI OPR PATTERN File: 13.787.00
VSAPI OPR PATTERN Date: 17 Nov 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

Disable this malware service

[ Learn More ]
    • {Malware File Name}

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_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\WMI\Security
    • 125463f3-2a9c-bdf0-d890-5a98b08d8898 = "{Hexadecimal Values}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\WMI\Security
    • f0012345-2a9c-bdf8-345d-345d67b542a1 = "{Hexadecimal Values}"

Step 5

Scan your computer with your Trend Micro product to delete files detected as BKDR_VOLGMER.W. 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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