arrow_back
search
close

Backdoor.Win32.ZEGOST.ANE

October 12, 2019
 PLATFORM:

Windows

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

  • 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:

1,200,128 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

12 Oct 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:

  • %System Root%\$WinBackUP.H0808\secsv.exe

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

It adds the following processes:

  • rundll32.exe %System%\shimgvw.dll,ImageView_Fullscreen %System Root%\$WinBackUP.H0808\applY.jpg
  • %System Root%\$WinBackUP.H0808\secsv.exe

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

It creates the following folders:

  • %AppDataLocal%\Microsoft\Windows\Explorer
  • %System Root%\$RECYLLE.BIN
  • %System Root%\SkySky
  • %System Root%\Program Files\AppPatch
  • %System Root%\$WinBackUP.H0808
  • %System Root%\system

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 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 System Modifications

This Backdoor deletes the following files:

  • %System Root%\$WinBackUP.H0808\secsv.exe

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

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
FileExts\.jpg\OpenWithProgids\
jpegfile

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wshezh euimwurf

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
KeyFileName = "{malware path and file name}.dat"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\MuiCache\
%Program Files%\Windows Photo Viewer
PhotoViewer.dll = "Windows Photo Viewer"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\MuiCache\
%System%
mspaint.exe = "Paint"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\MuiCache\
%Windows%\eHome
ehshell.exe = "Windows Media Center"

HKEY_CURRENT_USER\Software\Classes\
Local Settings\Software\Microsoft\
Windows\Shell\MuiCache\
%Program Files%\MICROS~1\Office12
OIS.EXE = "Microsoft Office Picture Manager"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Wshezh euimwurf
ConnectGroup = "{random characters}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Wshezh euimwurf
MarkTime = "2019-06-14 00:17"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
KeyName = "KeyValue"

Dropping Routine

This Backdoor drops the following files:

  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_32.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_96.db
  • %AppDataLocal%\GDIPFONTCACHEV1.DAT
  • %System Root%\$RECYLLE.BIN\TorchWooc
  • %System Root%\system\Consys21.png
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_256.db
  • %System Root%\$WinBackUP.H0808\applY.jpg
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_1024.db
  • %System Root%\Program Files\AppPatch\NHQDXZKK.jpg
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_sr.db
  • %System Root%\Program Files\AppPatch\NHQDXZK.jpg
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_idx.db

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 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://www.{BLOCKED}168.com/XXKJ/NHQDXZKK.jpg
  • http://www.{BLOCKED}168.com/XXKJ/NHQDXZK.jpg
  • http://www.{BLOCKED}2.com

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.850

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 Backdoor.Win32.ZEGOST.ANE

[ 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

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.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.jpg\OpenWithProgids
    • jpegfile
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • Wshezh euimwurf

Step 4

Delete this registry value

[ 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.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
    • KeyFileName = "{malware path and file name}.dat"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\MuiCache\%Program Files%\Windows Photo Viewer
    • PhotoViewer.dll = "Windows Photo Viewer"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\MuiCache\%System%
    • mspaint.exe = "Paint"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\MuiCache\%Windows%\eHome
    • ehshell.exe = "Windows Media Center"
  • In HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\MuiCache\%Program Files%\MICROS~1\Office12
    • OIS.EXE = "Microsoft Office Picture Manager"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Wshezh euimwurf
    • ConnectGroup = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Wshezh euimwurf
    • MarkTime = "2019-06-14 00:17"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
    • KeyName = "KeyValue"

Step 5

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.
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_32.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_96.db
  • %AppDataLocal%\GDIPFONTCACHEV1.DAT
  • %System Root%\$RECYLLE.BIN\TorchWooc
  • %System Root%\system\Consys21.png
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_256.db
  • %System Root%\$WinBackUP.H0808\applY.jpg
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_1024.db
  • %System Root%\Program Files\AppPatch\NHQDXZKK.jpg
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_sr.db
  • %System Root%\Program Files\AppPatch\NHQDXZK.jpg
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_idx.db

Step 6

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %AppDataLocal%\Microsoft\Windows\Explorer
  • %System Root%\$RECYLLE.BIN
  • %System Root%\SkySky
  • %System Root%\Program Files\AppPatch
  • %System Root%\$WinBackUP.H0808
  • %System Root%\system

Step 7

Scan your computer with your Trend Micro product to delete files detected as Backdoor.Win32.ZEGOST.ANE. 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:

Step 8

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%\$WinBackUP.H0808\secsv.exe


Did this description help? Tell us how we did.