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BKDR_SCYTI.A

February 16, 2016
 Analysis by: Homer Pacag
 ALIASES:

RDN/Generic BackDoor (McAfee); Backdoor.Trojan (Symantec);

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW


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.

  TECHNICAL DETAILS

File Size:

851,968 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

12 Feb 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 drops the following files:

  • %Program Files%\dataup\dataup.ini
  • %Program Files%\dataup\NTSVC.ocx
  • %Program Files%\taskvmx\taskvmx.exe

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It drops and executes the following files:

  • %Program Files%\dataup\dataup.exe
  • %Program Files%\regtool\regtool.exe

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

It creates the following folders:

  • %Program Files%\dataup
  • %Program Files%\regtool
  • %Program Files%\taskvmx

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Autostart Technique

This backdoor registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\windowsmanagementservice
ImagePath = "{Malware Path\Malware Filename.exe}" /svc

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\windowsmanagementservice
DisplayName = Windows Management Service

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\windowsmanagementservice
Description = Provides management service for system.

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Dataup
ImagePath = %Program Files%\dataup\dataup.exe

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Dataup
DisplayName = Dataup Service

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Dataup
Description = Detect version consistency of client and server, and get the latest version from the server.

Other System Modifications

This backdoor also creates the following registry entry(ies) as part of its installation routine:

HKLM\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
cpx = "%Program Files%\cpx\cpx.exe" -starup

HKLM\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
msrtn32 = "%Program Files%\msrtn32\msrtn32.exe" -startup=smartcpx -check=60

Download Routine

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

  • http://d1.{BLOCKED}edtrk.com/p/dataup.zip
  • http://d1.{BLOCKED}edtrk.com/p/regtool.zip
  • http://d1.{BLOCKED}edtrk.com/p/taskvmx.zip

It saves the files it downloads using the following names:

  • %Program Files%\dataup\dataup.zip
  • %Program Files%\regtool\regtool.zip
  • %Program Files%\taskvmx\taskvmx.zip

(Note: %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.)

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://{BLOCKED}b.com/report.php
  • http://www.{BLOCKED}be.com/databack.php
  • http://{BLOCKED}st.com:8080/arg.lp
  • http://www.{BLOCKED}7.com/report.php
  • http://www.{BLOCKED}n.com:8080/rep001.lp

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.338.03

FIRST VSAPI PATTERN DATE:

12 Feb 2016

VSAPI OPR PATTERN File:

12.333.00

VSAPI OPR PATTERN Date:

12 Feb 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

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

 
  • HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\windowsmanagementservice
  • HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\Dataup
  • HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\cpx
  • HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\msrtn32

Step 5

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.
  • %Program Files%\dataup
  • %Program Files%\regtool
  • %Program Files%\taskvmx

Step 6

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.
  • %Program Files%\dataup\dataup.exe
  • %Program Files%\dataup\dataup.ini
  • %Program Files%\dataup\NTSVC.ocx
  • %Program Files%\regtool\regtool.exe
  • %Program Files%\taskvmx\taskvmx.exe

Step 7

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