Analysis by: Pearl Charlaine Espejo

ALIASES:

Backdoor:Win32/Bedep!rfn (Microsoft); Backdoor.Win32.Bedep.kun (Kaspersky); Trojan.Bedep (Malwarebytes); Win32.Backdoor.Bedep.Amcp (Tencent)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • 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 requires its main component to successfully perform its intended routine. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 264,704 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 19 May 2016
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 drops the following files:

  • %All Users Profile%\Application Data\{UID}\{random characters}

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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:

  • %All Users Profile%\Application Data\{UID}

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData 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.)

Other Details

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

  • http://www.msftncsi.com/ncsi.txt

It connects to the following possibly malicious URL:

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

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

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

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.540.05
FIRST VSAPI PATTERN DATE: 21 May 2016
VSAPI OPR PATTERN File: 12.541.00
VSAPI OPR PATTERN Date: 22 May 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

Restart in Safe Mode

[ Learn More ]

Step 3

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.  
  • %All Users Profile%\Application Data\{UID}

Step 4

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