BKDR_SYSCON.A


 ALIASES:

Gen:Trojan.Heur.LP.au4@aW6Y!mi (Bitdefender)

 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

Infection Channel:

Dropped by other malware

This Backdoor may be dropped by other malware.

  TECHNICAL DETAILS

File Size:

13,824 bytes

File Type:

DLL

Memory Resident:

No

Initial Samples Received Date:

19 Sep 2017

Payload:

Connects to URLs/IPs, Terminates processes, Adds processes

Arrival Details

This Backdoor may be dropped by the following malware:

  • W2KM_SYSCON.A

Installation

This Backdoor drops the following files:

  • %User Temp%\temp.ini -> contains system info and task list
  • %User Temp%\{8 random characters} -> archived temp.ini(deleted afterwards)
  • %User Temp%\temp.zip -> temporary archive (deleted afterwards)
  • %User Temp%\post.txt -> encrypted temp.ini(deleted afterwards)

(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 adds the following processes:

  • cmd /c taskkill /im cliconfg.exe /f /t
  • cmd /c taskkill /im sysprep.exe /f /t
  • cmd /c REG ADD HKCU\Console /v CodePage /t REG_DWORD /d 65001 /f
  • cmd /c systeminfo >%User Temp%\temp.ini
  • cmd /c tasklist >%User Temp%\temp.ini

(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 System Modifications

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

HKEY_CURRENT_USER\Console
CodePage = "65001"

Process Termination

This Backdoor terminates the following processes if found running in the affected system's memory:

  • sysprep.exe
  • cliconfg.exe

Other Details

This Backdoor does the following:

  • It connects to the FTP with the following credentials:
    • Server Name: ftp.{BLOCKED}st12.com
    • Server Port: 15
    • Username: b12_20618720
    • Password: qwerASDF
  • It changes the current directory in the FTP to "/htdocs/"
  • It repeatedly sends the file post.txt to the FTP containing the following details:
    • system informations
    • list of tasks
  • It sends the file and renames it to:
    • {Computer Name} (MM-DD hh-mm-ss).txt
  • It downloads files from the FTP with the info “to everyone”

  SOLUTION

Minimum Scan Engine:

9.850

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_SYSCON.A

[ 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 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\Console
    • CodePage = "65001"

Step 5

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%\temp.ini
  • %User Temp%\{8 random characters}
  • %User Temp%\temp.zip
  • %User Temp%\post.txt

Step 6

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