Analysis by: RonJay Kristoffer Caragay
ALIASES:

Backdoor:Win32/Bedep.A (Microsoft); Backdoor.Win32.Bedep.ajn (Kaspersky); Win32/Bedep.D (ESET-NOD32); W32/Bedep.D!tr (Fortinet); Trojan.Win32.Bedep (Ikarus); TR/Bedep.A.143 (Avira);

 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, 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 does not have any propagation routine.

It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information. However, as of this writing, the said sites are inaccessible.

It requires its main component to successfully perform its intended routine.

  TECHNICAL DETAILS

File Size: 278,528 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 16 Jun 2015
Payload: Connects to URLs/IPs

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.

Installation

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

  • Global\{GUID}

It injects codes into the following process(es):

  • explorer.exe
  • iexplore.exe

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

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

  • initialize conneciton
  • download and execute arbitrary files
  • update self with click fraud module
  • report information

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

  • http://{random generated domain}.com/{URI}

It posts the following information to its command and control (C&C) server:

  • buildId
  • botId
  • processor (32 or 64-bit)
  • OS version
  • Protocol Version
  • Cookie

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

Other Details

This backdoor requires its main component to successfully perform its intended routine.

NOTES:

This backdoor accesses the following websites to get data that will be used to generate {random generated domain}:

  • http://www.ecb.europa.eu/stats/eurofxref/eurofxref-hist-90d.xml?{hex values}
  • http://www.earthtools.org/timezone-1.1/{random latitude}/{random longtitude}

It does not have rootkit capabilities.

The downloaded click fraud module is used to communicate with advertisement fraud servers to access various ads.

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 11.790.01
FIRST VSAPI PATTERN DATE: 14 Jul 2015
VSAPI OPR PATTERN File: 11.791.00
VSAPI OPR PATTERN Date: 15 Jul 2015

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

Scan your computer with your Trend Micro product and note files detected as BKDR_BEDEP.YWB

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete the files detected as BKDR_BEDEP.YWB

*Note: Some component files may be 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.

To stop the malware/grayware from running when certain files are opened:

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Right-click Start then click Search....
  2. In the File name* input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012 (R2):

  1. Open a Windows Explorer window.
    • For Windows Vista, 7, and Server 2008 users, click Start>Computer.
    • For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen,then click File Explorer.
  2. In the Search Computer/This PC input box, type the name of the file that was detected earlier.
  3. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 5

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