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: Downloaded from the Internet, Dropped by other malware

This backdoor contains a list of user names and passwords which it uses in its attempt to grant access to the System Root folder of an infected machine. It also installs another backdoor on the system. It is implicated in the Sony Pictures December 2014 attack.

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 the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size: 268,579 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 03 Dec 2014
Payload: Drops files, Compromises system security

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.

Autostart Technique

This backdoor registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinsSchMgmt
ImagePath = "{malware path and filename} -k"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinsSchMgmt
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinsSchMgmt
DisplayName = "Windows Schedule Management Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinsSchMgmt
ObjectName = "LocalSystem"

It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinsSchMgmt
ImagePath = "{malware path and filename} -k"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinsSchMgmt
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinsSchMgmt
DisplayName = "Windows Schedule Management Service"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinsSchMgmt
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WinsSchMgmt
Description = "Windows Schedule Management Service"

Dropping Routine

This backdoor drops the following files:

  • {malware path}\igfxtrayex.exe - detected as BKDR_WIPALL.B
  • %System%\net_ver.dat - contains the following information:
    hostname | IP Address | 2

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It executes the dropped file(s). As a result, malicious routines of the dropped files are exhibited on the affected system.

Other Details

This backdoor connects to the following website to send and receive information:

  • {BLOCKED}.{BLOCKED}.215.64
  • {BLOCKED}.{BLOCKED}.33.164
  • {BLOCKED}.{BLOCKED}.222.102

NOTES:

This backdoor accepts any of the following arguments:

  • -i
  • -k
  • -s

It attempts to log into shared network using a list of user names and passwords. Once logged in, it grants full access to the machine's System Root folder to everyone on the network.

  SOLUTION

Minimum Scan Engine: 9.700
FIRST VSAPI PATTERN FILE: 11.316.07
FIRST VSAPI PATTERN DATE: 03 Dec 2014
VSAPI OPR PATTERN File: 11.317.00
VSAPI OPR PATTERN Date: 03 Dec 2014

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

Remove the malware/grayware file dropped/downloaded by BKDR_WIPALL.A. (Note: Please skip this step if the threat(s) listed below have already been removed.)

    • BKDR_WIPALL.B

Step 4

Restart in Safe Mode

[ Learn More ]

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

 
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • WinsSchMgmt

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_WIPALL.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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