BKDR_PLUGX.KA
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted:
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.
It deletes itself after execution.
TECHNICAL DETAILS
390,003 bytes
EXE
No
09 Jul 2015
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 creates the following folders:
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\Wilbert
- %User Profile%\LOCALS~1
- %User Temp%\RarSFX0
- %User Profile%\DRM
- %User Profile%\DRM\oLd
(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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 deletes the following files:
- %System Root%\fsguidll.exe
- %System Root%\fslapi.dll
- %System Root%\fslapi.dll.gui
- %User Temp%\RarSFX0\fsguidll.exe
- %User Temp%\RarSFX0\fslapi.dll
- %User Temp%\RarSFX0\fslapi.dll.gui
(Note: %System Root% is the Windows root folder, where it usually is C:\ 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.)
It adds the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
5.0\User Agent\Post Platform
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings\
User Agent\Post Platform
Dropping Routine
This backdoor drops the following files:
- __tmp_rar_sfx_access_check_387843
- fsguidll.exe
- fslapi.dll
- fslapi.dll.gui
- %User Profile%\oLd\fslapi.dll
- %User Profile%\oLd\fslapi.dll.gui
- %User Profile%\oLd\fsguidll.exe
- %User Profile%\oLd\whsdyptsjxgsh
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Other Details
This backdoor connects to the following possibly malicious URL:
- http://www.{BLOCKED}k.top/BCF48D913219CA3CA73F06E8
- http://www.{BLOCKED}k.top/13620B05888747B1FDAC845B
- http://www.{BLOCKED}k.top/2B9F6EC2A0C3AB6E15E8E817
- {BLOCKED}8.0.1
- {BLOCKED}8.0.2
- {BLOCKED}8.0.3
- {BLOCKED}8.0.4
- {BLOCKED}8.0.5
- {BLOCKED}8.0.6
- {BLOCKED}6.232.116
- {BLOCKED}8.0.7
- {BLOCKED}8.0.8
- {BLOCKED}8.0.9
- {BLOCKED}8.0.10
- {BLOCKED}8.0.11
- {BLOCKED}8.0.12
- {BLOCKED}8.0.13
- {BLOCKED}8.0.14
- {BLOCKED}8.0.15
- {BLOCKED}8.0.16
- {BLOCKED}8.0.17
- {BLOCKED}8.0.18
- {BLOCKED}8.0.19
- {BLOCKED}8.0.20
- {BLOCKED}8.0.21
- {BLOCKED}8.0.22
- {BLOCKED}8.0.23
- {BLOCKED}8.0.24
- {BLOCKED}8.0.25
- {BLOCKED}8.0.26
- {BLOCKED}8.0.27
- {BLOCKED}8.0.28
- {BLOCKED}8.0.29
- {BLOCKED}8.0.30
It deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
9.750
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
Delete this registry key
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\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\5.0\User Agent
- Post Platform
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\User Agent
- Post Platform
Step 3
Search and delete these components
- __tmp_rar_sfx_access_check_387843
- fsguidll.exe
- fslapi.dll
- fslapi.dll.gui
- %User Profile%\oLd\fslapi.dll
- %User Profile%\oLd\fslapi.dll.gui
- %User Profile%\oLd\fsguidll.exe
- %User Profile%\oLd\whsdyptsjxgsh
Step 4
Search and delete these folders
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\Wilbert
- %User Profile%\LOCALS~1
- %User Temp%\RarSFX0
- %User Profile%\DRM
- %User Profile%\DRM\oLd
Step 5
Scan your computer with your Trend Micro product to delete files detected as BKDR_PLUGX.KA. 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.
Step 6
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %System Root%\fsguidll.exe
- %System Root%\fslapi.dll
- %System Root%\fslapi.dll.gui
- %User Temp%\RarSFX0\fsguidll.exe
- %User Temp%\RarSFX0\fslapi.dll
- %User Temp%\RarSFX0\fslapi.dll.gui
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