BKDR_TELEBOT.B


 ALIASES:

Backdoor.Telebot (Symantec); Python/Agent.AE (ESET-NOD32);

 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.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

4,595,935 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

16 Dec 2016

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 adds the following folders:

  • %User Temp%\_MEI{random numbers}

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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 files:

  • %User Temp%\_MEI{random numbers}\_ctypes.pyd
  • %User Temp%\_MEI{random numbers}\_hashlib.pyd
  • %User Temp%\_MEI{random numbers}\_socket.pyd
  • %User Temp%\_MEI{random numbers}\_ssl.pyd
  • %User Temp%\_MEI{random numbers}\bz2.pyd
  • %User Temp%\_MEI{random numbers}\Crypto.Cipher._AES.pyd
  • %User Temp%\_MEI{random numbers}\Crypto.Hash._SHA256.pyd
  • %User Temp%\_MEI{random numbers}\Crypto.Random.OSRNG.winrandom.pyd
  • %User Temp%\_MEI{random numbers}\Crypto.Util._counter.pyd
  • %User Temp%\_MEI{random numbers}\Microsoft.VC90.CRT.manifest
  • %User Temp%\_MEI{random numbers}\msvcm90.dll
  • %User Temp%\_MEI{random numbers}\msvcp90.dll
  • %User Temp%\_MEI{random numbers}\msvcr90.dll
  • %User Temp%\_MEI{random numbers}\{random filename}.exe.manifest
  • %User Temp%\_MEI{random numbers}\pyexpat.pyd
  • %User Temp%\_MEI{random numbers}\python27.dll
  • %User Temp%\_MEI{random numbers}\pywintypes27.dll
  • %User Temp%\_MEI{random numbers}\requests\cacert.pem
  • %User Temp%\_MEI{random numbers}\select.pyd
  • %User Temp%\_MEI{random numbers}\unicodedata.pyd
  • %User Temp%\_MEI{random numbers}\win32api.pyd
  • %User Temp%\_MEI{random numbers}\win32pipe.pyd
  • %User Temp%\_MEI{random numbers}\win32wnet.pyd

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)

Backdoor Routine

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

  • upload - Get file from remote user to affected system
  • cmd - Perform remote shell command
  • forcecheckin - Get OS information
  • download - Send specified file from affected system to remote user

Download Routine

This backdoor saves the files it downloads using the following names:

  • {malware path}\+~JF{random}.exe

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Information Theft

This backdoor gathers the following data:

  • OS Platform Version
  • Process Architecture
  • Admintrator Privileges
  • User UID

Other Details

This backdoor drops the following file(s)/component(s):

  • {malware path}\log_{random} ← log file;

NOTES:

This backdoor uses the following Simple Mail Transfer Protocol (SMTP) servers to send information to remote malicious user:

  • smtp-mail.outlook.com

It uses the following Internet Message Access Protocol (IMAP) servers to receive command from remote malicious user:

  • imap-mail.outlook.com

It sends and receives information using the following email address:

  • {BLOCKED}akeieva@outlook.com

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

13.124.07

FIRST VSAPI PATTERN DATE:

30 Dec 2016

VSAPI OPR PATTERN File:

13.125.00

VSAPI OPR PATTERN Date:

30 Dec 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

Search and delete this folder

[ 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.  
  • %User Temp%\_MEI{random numbers}

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.
  • {malware path}\log_{random}
  • {malware path}\+~JF{random}.exe

Step 6

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