BKDR_BANDOK.C

June 05, 2018
 Modified by: Kiyoshi Obuchi
 ALIASES:

Backdoor.W32.Bandok!c (AegisLab); Backdoor.Win32.Bandok.d (Kaspersky); Artemis!10939AE4103C (McAfee)

 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.

  TECHNICAL DETAILS

File Size:

5,325 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

26 Apr 2012

Payload:

Connects to URLs/IPs, Steals 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:

  • %System%\ali.exe

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

It drops the following files:

  • %System Root%\ali.html -> {deleted afterwards}

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

It adds the following processes:

  • {Default Browser}

It injects codes into the following process(es):

  • {Default Browser} (added process)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{B6A807N6-42DF-4W02-93E5-B156B3FA8AL1}
StubPath = "%System%\ali.exe"

Backdoor Routine

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

  • Close Socket
  • Sends reply (own ping function)
  • Deletes created registries and exits process
  • Downloads a file and executes it
  • Gets processes list
  • Terminates process
  • Deletes downloaded files

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

  • http://who.{BLOCKED}p.com

As of this writing, the said sites are inaccessible.

Information Theft

This Backdoor gathers the following data:

  • Username
  • IP address
  • Computer Name

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

9.746.01

FIRST VSAPI PATTERN DATE:

06 Jul 2012

VSAPI OPR PATTERN File:

9.747.00

VSAPI OPR PATTERN Date:

07 Jul 2012

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{B6A807N6-42DF-4W02-93E5-B156B3FA8AL1}
    • StubPath = "%System%\ali.exe"

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.
  • %System Root%\ali.html

Step 6

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