TROJ_CHKBOT.NA
Trojan:Win32/ChkBot.A (Microsoft); Generic.mem (McAfee); Trojan.Gen (Symantec); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Atros3.LGA (AVG)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan 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
Arrival Details
This Trojan 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 Trojan creates the following folders:
- %User Profile%\Application Data\HyhotbUrls
- %User Profile%\HyhotbUrls\Zyuan
- %Program Files%\oA848pt3preqfO
- %Windows%\KomLxiu
- %User Profile%\Application Data\tmpst
- %User Profile%\Application Data\SQ PlatForm
(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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
oA848pt3preqfO = "%Program Files%\oA848pt3preqfO\oA848pt3preqfO.exe"
Other System Modifications
This Trojan deletes the following files:
- %System Root%\SESP20~1.EXE
- %System Root%\SESP20~1.BAT
- %System Root%\SETUP_~1.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 Script\Settings
HKEY_CURRENT_USER\Software\MyCaseGet
HKEY_CURRENT_USER\Software\oA848pt3preqfO
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\Game_Zhang_121
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\Game_Zhang_121\
DEBUG
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows Script\Settings
JITDebug = "0"
HKEY_CURRENT_USER\Software\MyCaseGet
9977843 = "0"
HKEY_CURRENT_USER\Software\oA848pt3preqfO
AppPath = "%Program Files%\oA848pt3preqfO"
HKEY_CURRENT_USER\Software\oA848pt3preqfO
AboutUs = "50006"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
EventMessageFile = "%System%\ESENT.dll"
(Note: The default value data of the said registry entry is {random values}.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryMessageFile = "%System%\ESENT.dll"
(Note: The default value data of the said registry entry is {random values}.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryCount = "1"
(Note: The default value data of the said registry entry is 10.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
TypesSupported = "7"
(Note: The default value data of the said registry entry is 7.)
Dropping Routine
This Trojan drops the following files:
- %System Root%\Sesp203_nv_u.exe
- %System Root%\setup_50006.exe
- %System Root%\Game_Zhang_121.exe
- %System Root%\sevice_905_45078.exe
- %User Profile%\HyhotbUrls\EdncajGsqxz.exe
- %User Profile%\HyhotbUrls\Zyuan/back.jpg
- %User Profile%\HyhotbUrls\Zyuan/close.jpg
- %User Profile%\HyhotbUrls\Zyuan/close.png
- %User Profile%\HyhotbUrls\Zyuan/config.ini
- %User Profile%\HyhotbUrls\Zyuan/ground.jpg
- %User Profile%\HyhotbUrls\Zyuan/logo.png
- %User Profile%\HyhotbUrls\Zyuan/min.png
- %User Profile%\HyhotbUrls\Zyuan/name.png
- %User Profile%\HyhotbUrls\Zyuan/skin
- %User Profile%\HyhotbUrls\Zyuan/title.jpg
- %User Profile%\HyhotbUrls\SeinynH0encnae
- %System Root%\Sesp203_nv_u.exe.bat
- %Program Files%\oA848pt3preqfO\oA848pt3preqfO.dat
- %Program Files%\oA848pt3preqfO\oA848pt3preqfO.exe
- %Desktop%\????.exe
- %Program Files%\oA848pt3preqfO\GetMyApp.dat
- %Program Files%\oA848pt3preqfO\GetMyApp.exe
- %Windows%\KomLxiu\Houzik.sys
- %User Profile%\tmpst\shst
- %User Temp%\110kk011
- %User Profile%\SQ PlatForm\9042399501616174882
- %User Profile%\SQ PlatForm\5
- %User Profile%\SQ PlatForm\4355426151826907678
- %User Profile%\SQ PlatForm\5819387593380388219
(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.. %Program Files% is the Program Files folder, where it usually is C:\Program Files on all Windows operating system versions; C:\Program Files (x86) for 32-bit applications running on Windows 64-bit operating systems.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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.. %Windows% is the Windows folder, where it usually is C:\Windows 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.)
Other Details
This Trojan connects to the following possibly malicious URL:
- {BLOCKED}9.242.216
- {BLOCKED}.157.233
- {BLOCKED}.252.60
- {BLOCKED}.45.159
- {BLOCKED}6.10.224
- {BLOCKED}7.220.151
- {BLOCKED}8.250.122
- {BLOCKED}4.40.46
- {BLOCKED}6.44.44
This report is generated via an automated analysis system.
SOLUTION
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
Restart in Safe Mode
Step 3
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 Script
- Settings
- In HKEY_CURRENT_USER\Software
- MyCaseGet
- In HKEY_CURRENT_USER\Software
- oA848pt3preqfO
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process
- Game_Zhang_121
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process\Game_Zhang_121
- DEBUG
Step 4
Delete this registry value
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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- oA848pt3preqfO = "%Program Files%\oA848pt3preqfO\oA848pt3preqfO.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows Script\Settings
- JITDebug = "0"
- In HKEY_CURRENT_USER\Software\MyCaseGet
- 9977843 = "0"
- In HKEY_CURRENT_USER\Software\oA848pt3preqfO
- AppPath = "%Program Files%\oA848pt3preqfO"
- In HKEY_CURRENT_USER\Software\oA848pt3preqfO
- AboutUs = "50006"
Step 5
Restore these modified registry values
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\ControlSet001\Services\Eventlog\Application\ESENT
- From: EventMessageFile = "%System%\ESENT.dll"
To: EventMessageFile = ""{random values}""
- From: EventMessageFile = "%System%\ESENT.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: CategoryMessageFile = "%System%\ESENT.dll"
To: CategoryMessageFile = ""{random values}""
- From: CategoryMessageFile = "%System%\ESENT.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: CategoryCount = "1"
To: CategoryCount = ""10""
- From: CategoryCount = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: TypesSupported = "7"
To: TypesSupported = ""7""
- From: TypesSupported = "7"
Step 6
Search and delete these components
- %System Root%\Sesp203_nv_u.exe
- %System Root%\setup_50006.exe
- %System Root%\Game_Zhang_121.exe
- %System Root%\sevice_905_45078.exe
- %User Profile%\HyhotbUrls\EdncajGsqxz.exe
- %User Profile%\HyhotbUrls\Zyuan/back.jpg
- %User Profile%\HyhotbUrls\Zyuan/close.jpg
- %User Profile%\HyhotbUrls\Zyuan/close.png
- %User Profile%\HyhotbUrls\Zyuan/config.ini
- %User Profile%\HyhotbUrls\Zyuan/ground.jpg
- %User Profile%\HyhotbUrls\Zyuan/logo.png
- %User Profile%\HyhotbUrls\Zyuan/min.png
- %User Profile%\HyhotbUrls\Zyuan/name.png
- %User Profile%\HyhotbUrls\Zyuan/skin
- %User Profile%\HyhotbUrls\Zyuan/title.jpg
- %User Profile%\HyhotbUrls\SeinynH0encnae
- %System Root%\Sesp203_nv_u.exe.bat
- %Program Files%\oA848pt3preqfO\oA848pt3preqfO.dat
- %Program Files%\oA848pt3preqfO\oA848pt3preqfO.exe
- %Desktop%\????.exe
- %Program Files%\oA848pt3preqfO\GetMyApp.dat
- %Program Files%\oA848pt3preqfO\GetMyApp.exe
- %Windows%\KomLxiu\Houzik.sys
- %User Profile%\tmpst\shst
- %User Temp%\110kk011
- %User Profile%\SQ PlatForm\9042399501616174882
- %User Profile%\SQ PlatForm\5
- %User Profile%\SQ PlatForm\4355426151826907678
- %User Profile%\SQ PlatForm\5819387593380388219
Step 7
Search and delete these folders
- %User Profile%\Application Data\HyhotbUrls
- %User Profile%\HyhotbUrls\Zyuan
- %Program Files%\oA848pt3preqfO
- %Windows%\KomLxiu
- %User Profile%\Application Data\tmpst
- %User Profile%\Application Data\SQ PlatForm
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CHKBOT.NA. 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 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.
- %System Root%\SESP20~1.EXE
- %System Root%\SESP20~1.BAT
- %System Root%\SETUP_~1.EXE
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