Analysis by: Francis Xavier Antazo

 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 runs certain commands that it receives remotely from a malicious user. Doing this puts the affected computer and information found on the computer at greater risk. It connects to a website to send and receive information.

It gathers information and reports it to its servers.

  TECHNICAL DETAILS

File Size: 7962000 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 02 Jun 2016
Payload: Connects to URLs/IPs, Downloads files, 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 component file(s):

  • %Application Data%\arrow1.cur
  • %Application Data%\date.dat
  • %Application Data%\link1.cur
  • %Application Data%\select1.cur
  • %Application Data%\semtitulo.cur
  • %Application Data%\winup00.dat
  • %Application Data%\winupdate.dat
  • %Desktop%\%Application Data%\{random file name 1}.exe.lnk

(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.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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 copies of itself into the affected system:

  • %All Users Profile%\Microsoft\Windows\Start Menu\Programs\Startup\{random file name 1}.exe
  • %Application Data%\{random file name 1}.exe
  • %Program Data%\Microsoft\Windows\Start Menu\Programs\Startup\{random file name 1}.exe

(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.. %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:

  • SW2016

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random file name 2} = "%Application Data%\{random file name 1}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random file name 2} = "%Application Data%\{random file name 1}.exe"

It drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:

  • C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup\{random file name 1}.exe.lnk
  • %All Users Profile%\Microsoft\Windows\Start Menu\Programs\Startup\{random file name 1}.exe.lnk

(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.)

Backdoor Routine

This backdoor executes the following command(s) from a remote malicious user:

  • Clipboard log
  • Keyboard log
  • Snapshot
  • File Manipulation (Create, Modify, Delete)
  • Execute Shell comands

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

  • http://www.{BLOCKED}m.org.cn/libraries/pear/graph.php

Download Routine

This backdoor connects to the following website(s) to download and execute a malicious file:

  • http://www.foschiattisrl.it/libraries/phputf8/utils/JK2017.exe

It saves the files it downloads using the following names:

  • %User Temp%\{random file name 3}.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.)

Other Details

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

  • http://meuip.net.br/
  • http://www.qualmeuip.com.br/

It gathers the following information and reports it to its servers:

  • Username
  • Computer name
  • Installed AV
  • Plugins
  • Processor info
  • Os Version
  • External IP
  • Date

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.590.07
FIRST VSAPI PATTERN DATE: 14 Jun 2016
VSAPI OPR PATTERN File: 12.591.00
VSAPI OPR PATTERN Date: 15 Jun 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 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.  
  • %Application Data%\arrow1.cur
  • %Application Data%\date.dat
  • %Application Data%\link1.cur
  • %Application Data%\select1.cur
  • %Application Data%\semtitulo.cur
  • %Application Data%\winup00.dat
  • %Application Data%\winupdate.dat
  • %Desktop%\%Application Data%\{random file name 1}.exe.lnk
  • C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup\{random file name 1}.exe.lnk
  • %All Users Profile%\Microsoft\Windows\Start Menu\Programs\Startup\{random file name 1}.exe.lnk

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random file name 2} = "%Application Data%\{random file name 1}.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {random file name 2} = "%Application Data%\{random file name 1}.exe"

Step 6

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