BKDR_ALINA.POSKAT

 Analysis by: Anthony Joe Melgarejo

 ALIASES:

TrojanSpy:Win32/Alinaos.A (Microsoft)

 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, Dropped by other malware

This is the detection for the Katrina point-of-sale (PoS) malware.

To get a one-glance comprehensive view of the behavior of this Backdoor, refer to the Threat Diagram shown below.

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.

  TECHNICAL DETAILS

File Size:

303,616 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

24 Sep 2015

Payload:

Connects to URLs/IPs, Downloads files

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%\usercache\{file name}.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 drops the following files:

  • %Application Data%\bootstrap - encrypted copy of itself

(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.)

Autostart Technique

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

HKEY_CURRENT_USER\Microsoft\Windows\
CurrentVersion\Run
{file name} = "%Application Data%\usercache\{file name}.exe

Other System Modifications

This backdoor adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DownloadManager

It adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
identifier = "{random 6 letters}"

Backdoor Routine

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

  • Update itself
  • Change interval of update requests
  • Change interval of card data exfiltration
  • Enable/Disable logging
  • Download and execute other malware

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • http://www.{BLOCKED}es777.ru/x1/settings.php

Download Routine

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

  • http://{BLOCKED}.{BLOCKED}.178.109/file/32.exe - detected as TSPY_POSNEWT.B
  • http://{BLOCKED}.{BLOCKED}.178.109/file/64.exe - detected as TSPY64_POSNEWT.B

It saves the files it downloads using the following names:

  • %Application Data%\{random file name}.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.)

NOTES:

It creates the following named pipe:

  • \.\\pipe\Katrina{random 6 letters}

{file name} can be any of the following:

  • svchost
  • java
  • jusched
  • jucheck
  • desktop
  • adobeflash
  • win-firewall
  • dwm
  • testing
  • userinit
  • windefender

It scans the memory of all running processes to retrieve card track data.

It skips to scan the following processes:

  • AKW.exe
  • QML.exe
  • spoolsv.exe
  • taskmgr.exe
  • wscntfy.exe
  • alg.exe
  • winlogon.exe
  • lsass.exe
  • dllhost.exe
  • services.exe
  • pidgin.exe
  • skype.exe
  • thunderbird.exe
  • devenv.exe
  • steam.exe
  • wininit.exe
  • csrss.exe
  • smss.exe
  • iexplore.exe
  • firefox.exe
  • chrome.exe
  • explorer.exe

It uses the following User-Agent:

  • Mozilla/5.0 (Windows NT 6.1; WOW64; rv:5.0) Gecko/20100101 Firefox/5.0

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

11.938.01

FIRST VSAPI PATTERN DATE:

24 Sep 2015

VSAPI OPR PATTERN File:

11.939.00

VSAPI OPR PATTERN Date:

25 Sep 2015

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_ALINA.POSKAT

[ 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

Remove malware/grayware files dropped/downloaded by BKDR_ALINA.POSKAT. (Note: Please skip this step if the threats listed below have already been removed.)

     
    • TSPY_POSNEWT.B
    • TSPY64_POSNEWT.B

Step 5

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_LOCAL_MACHINE\SOFTWARE\Microsoft
    • DownloadManager

Step 6

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\Microsoft\Windows\CurrentVersion\Run
    • {file name} = "%Application Data%\usercache\{file name}.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
    • identifier = "{random 6 letters}"

Step 7

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%\bootstrap

Step 8

Scan your computer with your Trend Micro product to delete files detected as BKDR_ALINA.POSKAT. 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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