TSPY_ZBOT.YUYAKC
Windows
Threat Type: Spyware
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This spyware 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
836,832 bytes
EXE
Yes
02 Nov 2015
Arrival Details
This spyware 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 spyware drops the following copies of itself into the affected system:
- %User Temp%\FolderName\file.exe
(Note: %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.)
It creates the following folders:
- %User Temp%\FolderName
- %User Profile%\Application Data\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B
- %Program Files%\NAT Monitor
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\Logs
- %User Profile%\Logs\Wilbert
(Note: %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.. %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.)
Autostart Technique
This spyware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
NAT Monitor = "%Program Files%\NAT Monitor\natmon.exe"
Other System Modifications
This spyware deletes the following files:
- %User Temp%\ svhost.exe
- %User Temp%\FolderName\file.exe:Zone.Identifier
- %User Startup%\file.exe:Zone.Identifier
- %User Profile%\NAT Monitor\natmon.exe
- %User Temp%\svhost.exe:Zone.Identifier
(Note: %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.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.. %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.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\WinRAR
It adds the following registry entries:
HKEY_CURRENT_USER\Software\WinRAR
HWID = "{random values}"
HKEY_CURRENT_USER\Software\WinRAR
Client Hash = "{random values}"
HKEY_CURRENT_USER\Software\WinRAR
4635DC0E5596B74C24EB89A66A4221C5 = "{random values}"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Load = "cmd /c %User Temp%\FolderName\file.exe"
Dropping Routine
This spyware drops the following files:
- %User Temp%\205375.exe
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\run.dat
- %User Temp%\FolderName\file.exe
(Note: %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.. %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.)
Other Details
This spyware connects to the following possibly malicious URL:
- {BLOCKED}4.71.22
This report is generated via an automated analysis system.
SOLUTION
9.750
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
- WinRAR
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
- NAT Monitor = "%Program Files%\NAT Monitor\natmon.exe"
- In HKEY_CURRENT_USER\Software\WinRAR
- HWID = "{random values}"
- In HKEY_CURRENT_USER\Software\WinRAR
- Client Hash = "{random values}"
- In HKEY_CURRENT_USER\Software\WinRAR
- 4635DC0E5596B74C24EB89A66A4221C5 = "{random values}"
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_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
- Load = "cmd /c %User Temp%\FolderName\file.exe"
Step 6
Search and delete these components
- %User Temp%\205375.exe
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\run.dat
- %User Temp%\FolderName\file.exe
Step 7
Search and delete these folders
- %User Temp%\FolderName
- %User Profile%\Application Data\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B
- %Program Files%\NAT Monitor
- %User Profile%\6ABCE574-4AFC-42C5-8AB9-5739A84D8A8B\Logs
- %User Profile%\Logs\Wilbert
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.YUYAKC. 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.
- %User Temp%\ svhost.exe
- %User Temp%\FolderName\file.exe:Zone.Identifier
- %User Startup%\file.exe:Zone.Identifier
- %User Profile%\NAT Monitor\natmon.exe
- %User Temp%\svhost.exe:Zone.Identifier
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