TROJ_KRYPTIK.XXYE

 Modified by: Joselyn Canuela

 ALIASES:

Trojan.GenericKD.4921787 (BitDefender), W32/Warezov.gen2!W32DL (Cyren), Trojan.GenericKD.4921787 (F-Secure), Artemis!5FC342AE267F (McAfee)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet


This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

543,232 bytes

File Type:

EXE

File Compression:

UPX

Memory Resident:

No

Initial Samples Received Date:

02 May 2017

Payload:

Drops files

Arrival Details

This Trojan 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 Trojan drops and executes the following files:

  • %Windows%\wmsa.exe - detected as BKDR_REMOSH.JC
  • %User Temp%\selfkill.bat - batch file to delete the malware
  • %System Root%\os.ipsec - contains IP security configuration (deleted after execution)
  • %System Root%\netbois.sdb - database for system settings configuration (deleted after execution)

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %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.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It adds the following processes:

  • cmd.exe /c net stop Windows32_Update
  • cmd.exe /c taskkill /f /im update64.exe
  • cmd.exe /c del /f /s /q c:\widnows\dell\svchost.exe
  • cmd.exe /c del /f /s /q c:\widnows\dell\run.bat
  • cmd.exe /c del /f /s /q c:\widnows\dell\update64.exe
  • cmd.exe /c del /f /s /q c:\widnows\dell\run64.bat
  • cmd.exe /c secedit /configure /db c:\netbois.sdb
  • cmd /c %User Temp%\selfkill.bat /max
  • cmd.exe /c netsh ipsec importpolicy %System Root%\os.ipsec
  • cmd.exe /c netsh ipsec static set policy name=445 assign=y
  • cmd.exe /c sc config wuauserv start=disabled
  • cmd.exe /c net stop wuauserv
  • cmd /c net user IUSR_ADMIN /del

(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.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Other Details

This Trojan deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

13.366.08

FIRST VSAPI PATTERN DATE:

27 Apr 2017

VSAPI OPR PATTERN File:

13.367.00

VSAPI OPR PATTERN Date:

28 Apr 2017

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

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%\selfkill.bat
  • %Windows%\wmsa.exe

Step 4

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