BKDR_GRAYBIRD.MZ

 Modified by: Kiyoshi Obuchi

 PLATFORM:

Windows

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

  • 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.

  TECHNICAL DETAILS

File Size:

468,992 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

24 May 2019

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 drops the following copies of itself into the affected system:

  • %Program Files%\Common Files\Microsoft Shared\MSInfo\macicsee.exe
  • %System%\_macicsee.exe
  • {Fixed drive}\macicsee.exe
  • %System Root%\macicsee.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

It adds the following processes:

  • %Program Files%\Common Files\Microsoft Shared\MSINFO\macicsee.exe
  • %Program Files%\Common Files\Microsoft Shared\MSINFO\Delet.bat
  • %System%\calc.exe
  • %Program Files%\internet explorer\IEXPLORE.EXE

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

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\macicse
DisplayName = "macicase"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\macicse
ImagePath = "%Program Files%\Common Files\Microsoft Shared\MSINFO\macicsee.exe"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\macicse
Start = "SERVICE_AUTO_START"

Other System Modifications

This Backdoor deletes the following files:

  • %System%\_macicsee.exe

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

Dropping Routine

This Backdoor drops the following files:

  • %Program Files%\Common Files\Microsoft Shared\MSInfo\Delet.bat
  • %System Root%\AutoRun.inf
  • {Fixed drive}\AutoRun.inf

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)

Other Details

This Backdoor connects to the following possibly malicious URL:

  • http://fengxing99.{BLOCKED}6.info

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

5.883.00

FIRST VSAPI PATTERN DATE:

08 Apr 2009

VSAPI OPR PATTERN File:

5.884.00

VSAPI OPR PATTERN Date:

09 Apr 2009

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 2

Identify and terminate files detected as BKDR_GRAYBIRD.MZ

[ 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 3

Search and delete these components

[ Learn More ]
There may be some components 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.
  • %Program Files%\Common Files\Microsoft Shared\MSInfo\Delet.bat
  • %System Root%\AutoRun.inf
  • {Fixed drive}\AutoRun.inf

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_GRAYBIRD.MZ. 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 the following Trend Micro Support pages for more information:


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