PUA.Win32.KuaiZip.LB.component


 ALIASES:

PUA.KpZip (Symantec); HEUR:AdWare.Win32.KuaiZip.gen (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Potentially Unwanted Application

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Potentially Unwanted Application 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:

227,792 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

03 Mar 2020

Arrival Details

This Potentially Unwanted Application 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 Potentially Unwanted Application adds the following processes:

  • %Windows%\SysWOW64\svchost.exe -k kuaizipupdatesvc
  • %Windows%\Microsoft.NET\Framework\v4.0.30319\mscorsvw.exe
  • %System%\svchost.exe -k LocalServiceAndNoImpersonation
  • %Windows%\Microsoft.NET\Framework64\v4.0.30319\mscorsvw.exe
  • %System%\sppsvc.exe
  • "%System Root%\Program Files\Windows Media Player\wmpnetwk.exe"
  • %System%\svchost.exe -k WerSvcGroup
  • %System%\svchost.exe -k netsvcs
  • %System%\svchost.exe -k LocalSystemNetworkRestricted
  • wlrmdr.exe -s -1 -f 2 -t You are about to be logged off -m Windows has encountered a critical problem and will restart automatically in one minute. Please save your work now. -a 3

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %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 creates the following folders:

  • %Windows%\ServiceProfiles\NetworkService\AppData\Local\Microsoft
  • %AppDataLocal%\Microsoft\Windows\Explorer

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

Autostart Technique

This Potentially Unwanted Application 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\KuaizipUpdateChecker
ImagePath = "%SystemRoot%\System32\svchost.exe -k kuaizipupdatesvc"

Other System Modifications

This Potentially Unwanted Application modifies the following file(s):

  • %Windows%\Tasks\SCHEDLGU.TXT

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

It deletes the following files:

  • %Windows%\LastGood.Tmp

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

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\KuaizipUpdateChecker
Description = "{random characters}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\KuaizipUpdateChecker\Parameters
ServiceDll = "%User Temp%\{malware file name}.dll"

HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows NT\CurrentVersion\
Svchost
kuaizipupdatesvc = ""

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\KuaizipUpdateChecker
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\KuaizipUpdateChecker
Type = "16"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\IKEEXT
Type = "16"

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\
KuaiZip\UpdateChecker
903ade86541bcd288342a2bbafbc8cd3 = "1572867872"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer
GlobalAssocChangedCounter = "41"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\ThemeManager
ServerChangeNumber = "61"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\LanmanServer\Shares
Users = "\x00\x00\x00\x00\x00\x00\x00"

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\
Microsoft\Windows\CurrentVersion\
ThemeManager
ThemeActive = "1"

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\
Microsoft\Windows\CurrentVersion\
ThemeManager
LoadedBefore = "1"

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\
Microsoft\Windows\CurrentVersion\
ThemeManager
LastUserLangID = "1033"

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\
Microsoft\Windows\CurrentVersion\
ThemeManager
LastLoadedDPI = "96"

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\
Microsoft\Windows\CurrentVersion\
ThemeManager
DllName = "%SystemRoot%\resources\Themes\Aero\Aero.msstyles"

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\
Microsoft\Windows\CurrentVersion\
ThemeManager
ColorName = "NormalColor"

HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\
Microsoft\Windows\CurrentVersion\
ThemeManager
SizeName = "NormalSize"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\KuaizipUpdateChecker
DisplayName = "KuaizipUpdateChecker"

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

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\Browser
Type = "16"

(Note: The default value data of the said registry entry is 20.)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\LanmanServer\Parameters
Guid = "\xd7\xc3$\x0b\xf6P\x88@\x94\xe7\xacrx\xd3\xba\xb6"

(Note: The default value data of the said registry entry is {random values}.)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\LanmanServer\Parameters\
Guid

Dropping Routine

This Potentially Unwanted Application drops the following files:

  • %System Root%\DfsServer
  • %Windows%\Tasks\SCHEDLGU.TXT
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_96.db
  • %AppDataLocal%\Microsoft\Media Player\CurrentDatabase_372.wmdb
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_sr.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_idx.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_256.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_1024.db
  • %All Users Profile%\Microsoft\Network\Downloader\qmgr1.dat
  • %All Users Profile%\Microsoft\Windows\DRM\v3ks.sec
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_32.db
  • %All Users Profile%\Microsoft\Windows\DRM\drmstore.hds
  • %All Users Profile%\Microsoft\Network\Downloader\qmgr0.dat

(Note: %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %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).. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

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 PUA.Win32.KuaiZip.LB.component

[ 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 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\KuaizipUpdateChecker
    • Description = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\KuaizipUpdateChecker\Parameters
    • ServiceDll = "%User Temp%\{malware file name}.dll"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Svchost
    • kuaizipupdatesvc = ""
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\KuaizipUpdateChecker
    • Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\KuaizipUpdateChecker
    • Type = "16"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\IKEEXT
    • Type = "16"
  • In HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\KuaiZip\UpdateChecker
    • 903ade86541bcd288342a2bbafbc8cd3 = "1572867872"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer
    • GlobalAssocChangedCounter = "41"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ThemeManager
    • ServerChangeNumber = "61"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Shares
    • Users = "\x00\x00\x00\x00\x00\x00\x00"
  • In HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\Microsoft\Windows\CurrentVersion\ThemeManager
    • ThemeActive = "1"
  • In HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\Microsoft\Windows\CurrentVersion\ThemeManager
    • LoadedBefore = "1"
  • In HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\Microsoft\Windows\CurrentVersion\ThemeManager
    • LastUserLangID = "1033"
  • In HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\Microsoft\Windows\CurrentVersion\ThemeManager
    • LastLoadedDPI = "96"
  • In HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\Microsoft\Windows\CurrentVersion\ThemeManager
    • DllName = "%SystemRoot%\resources\Themes\Aero\Aero.msstyles"
  • In HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\Microsoft\Windows\CurrentVersion\ThemeManager
    • ColorName = "NormalColor"
  • In HKEY_USERS\S-1-5-21-2407829820-1079796033-203259571-500\Software\Microsoft\Windows\CurrentVersion\ThemeManager
    • SizeName = "NormalSize"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\KuaizipUpdateChecker
    • DisplayName = "KuaizipUpdateChecker"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\KuaizipUpdateChecker
    • Start = "SERVICE_AUTO_START"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Browser
    • From: Type = "16"
      To: Type = ""20""
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Parameters
    • From: Guid = "\xd7\xc3$\x0b\xf6P\x88@\x94\xe7\xacrx\xd3\xba\xb6"
      To: Guid = ""{random values}""

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.
  • %System Root%\DfsServer
  • %Windows%\Tasks\SCHEDLGU.TXT
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_96.db
  • %AppDataLocal%\Microsoft\Media Player\CurrentDatabase_372.wmdb
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_sr.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_idx.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_256.db
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_1024.db
  • %All Users Profile%\Microsoft\Network\Downloader\qmgr1.dat
  • %All Users Profile%\Microsoft\Windows\DRM\v3ks.sec
  • %AppDataLocal%\Microsoft\Windows\Explorer\thumbcache_32.db
  • %All Users Profile%\Microsoft\Windows\DRM\drmstore.hds
  • %All Users Profile%\Microsoft\Network\Downloader\qmgr0.dat

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.
  • %Windows%\ServiceProfiles\NetworkService\AppData\Local\Microsoft
  • %AppDataLocal%\Microsoft\Windows\Explorer

Step 7

Scan your computer with your Trend Micro product to delete files detected as PUA.Win32.KuaiZip.LB.component. 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 deleted/modified files and/or registry entries from backup

*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

    • %Windows%\Tasks\SCHEDLGU.TXT

Step 9

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.

  • %Windows%\LastGood.Tmp

Step 10

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\LanmanServer\Parameters
    • Guid


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