TROJ_KRYPTIK.XXYE
Trojan.GenericKD.4921787 (BitDefender), W32/Warezov.gen2!W32DL (Cyren), Trojan.GenericKD.4921787 (F-Secure), Artemis!5FC342AE267F (McAfee)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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
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
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
- %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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