BKDR_HANCITOR.JUW

 Analysis by: Adrian Cofreros

 ALIASES:

Trojan:Win32/Chanitor.A(Microsoft),Trojan.Win32.Yakes.hqac(Kaspersky)

 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 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.

It gathers certain information on the affected computer.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

128,512 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

10 Jan 2015

Payload:

Connects to URLs/IPs, Compromises system security

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:

  • %Application Data%\Windows\winlogin.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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:

  • %Application Data%\Windows

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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 adds the following mutexes to ensure that only one of its copies runs at any one time:

  • 05F16C88-71D3-42C1-BB4F-E9BAF7DB4A9E

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
winlogin = "%Application Data%\Windows\winlogin.exe"

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
winlogin = "%Application Data%\Windows\winlogin.exe"

Other System Modifications

This backdoor adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\05F16C88-71D3-42C1-BB4F-E9BAF7DB4A9E

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\05F16C88-71D3-42C1-BB4F-E9BAF7DB4A9E
cfg = "{contains guid and computer name}"

Propagation

This backdoor does not have any propagation routine.

Backdoor Routine

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

  • Download file
  • Execute file
  • Uninstall itself(Delete drop copy, removing autostart registries)

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

  • http://{BLOCKED}zwu4or5mak.tor2web.ru:443/gate.php
  • http://{BLOCKED}zwu4or5mak.tor2web.org:443/gate.php

Download Routine

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

  • %User Temp%\___{random}.exe

(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.)

Information Theft

This backdoor gathers the following information on the affected computer:

  • Computer Name of affected system
  • IP address of Ethernet Network Interface

Other Details

This backdoor connects to the following URL(s) to get the affected system's IP address:

  • http://api.ipify.org:443

It deletes itself after execution.

NOTES:
It performs a command prompt to execute the following:

  • Ping local host 10 times
  • Execute downloaded file
  • Delete malware dropped copy

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

11.346.03

FIRST VSAPI PATTERN DATE:

15 Dec 2014

VSAPI OPR PATTERN File:

11.347.00

VSAPI OPR PATTERN Date:

16 Dec 2014

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

Identify and terminate files detected as BKDR_HANCITOR.JUW

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

Delete this registry key

[ 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_CURRENT_USER\Software\Microsoft\Active Setup\Installed Components
    • 05F16C88-71D3-42C1-BB4F-E9BAF7DB4A9E

Step 5

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\Windows\CurrentVersion\Run
    • winlogin = "%Application Data%\Windows\winlogin.exe"
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • winlogin = "%Application Data%\Windows\winlogin.exe"

Step 6

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.
  • %Application Data%\Windows

Step 7

Search and delete these files

[ 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.
  • %User Temp%\___{random}.exe

Step 8

Scan your computer with your Trend Micro product to delete files detected as BKDR_HANCITOR.JUW. 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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