TSPY_ZBOT.YUNKH
Win32/Spy.Zbot.AAU trojan (NOD32), VirTool:Win32/CeeInject.gen!KK (Microsoft), Trojan-Spy.Agent (Ikarus)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Spyware
Destructiveness: No
Encrypted: Yes
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.
It is injected into all running processes to remain memory resident.
It hides files, processes, and/or registry entries.
It steals certain information from the system and/or the user.
TECHNICAL DETAILS
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 non-malicious files:
- %Application Data%\Microsoft\Address Book\{user name}.wab
- %Application Data%\{random filename 2}.{random}
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
It drops the following copies of itself into the affected system:
- %User Temp%\{random folder name}\{random filename 1}.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It creates the following folders:
- %Application Data%\Microsoft\Address Book
- %User Temp%\{random folder name}
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It is injected into all running processes to remain memory resident.
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Local\{GUID}
- Global\{GUID}
Autostart Technique
This spyware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random} = ""%User Temp%\{random folder name}\{random filename 1}.exe""
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
{random}
HKEY_CURRENT_USER\Software\Microsoft\
WAB
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4\Wab File Name
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
{random}
{random} = "{random}"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkContactRefresh = "0"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkFolderRefresh = "0"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4\Wab File Name
(Default) = "%Application Data%\Microsoft\Address Book\{user name}.wab"
It creates the following registry entry(ies) to bypass Windows Firewall:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Windows%\explorer.exe = "%Windows%\explorer.exe:*:Enabled:Windows Explorer"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{random port 1}:UDP = "{random port 1}:UDP:*:Enabled:UDP {random port 1}"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{random port 2}:TCP = "{random port 2}:TCP:*:Enabled:TCP {random port 2}"
Rootkit Capabilities
This spyware hides files, processes, and/or registry entries.
Download Routine
This spyware connects to the following URL(s) to download its configuration file:
- http://{random generated URL}
Information Theft
This spyware steals the following information:
- Data on cookie files (URLs)
- Email-related information such as account names, email addresses, passwords, server data, and server port
- Email information stored in the user’s Windows Address Book (WAB) file
- Online banking credentials
- Personal digital cerificates
Other Details
This spyware connects to the following URL(s) to check for an Internet connection:
- http://google.com
- http://bing.com
It drops the following file(s)/component(s):
- %System%\driver\{random}.sys - detected as RTKT_NECURS.BGHW
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
NOTES:
This spyware attempts to download its configuration file by connecting to randomly generated URL.
The configuration file may contain URLs where it downloads an updated copy of itself and where it sends its gathered information.
It may also contain URLs of its target online banking and finance-related sites from where it steals the information.
It also collects information when it finds the following strings in certain applications:
- bancline
- bankman
- cruisenet
- dirclt32.exe
- episys
- fastdoc
- fdmaster.exe
- fidelity
- gplusmain
- jack henry
- launchpadshell.exe
- micrsolv
- pcsws.exe
- prologue.exe
- silverlake
- tellerplus
- v48d0250s1
- vantiv
- wtng.exe
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
Remove malware/grayware files dropped/downloaded by TSPY_ZBOT.YUNKH
- RTKT_NECURS.BGHW
Step 3
Restart in Safe Mode
Step 4
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
- {random}
- {random}
- In HKEY_CURRENT_USER\Software\Microsoft
- WAB
- WAB
Step 5
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random} = ""%User Temp%\{random folder name}\{random filename 1}.exe""
- {random} = ""%User Temp%\{random folder name}\{random filename 1}.exe""
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- %Windows%\explorer.exe = "%Windows%\explorer.exe:*:Enabled:Windows Explorer"
- %Windows%\explorer.exe = "%Windows%\explorer.exe:*:Enabled:Windows Explorer"
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {port1}:UDP = "{port1}:UDP:*:Enabled:UDP {port1}"
- {port1}:UDP = "{port1}:UDP:*:Enabled:UDP {port1}"
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {port2}:TCP = "{port2}:TCP:*:Enabled:TCP {port2}"
- {port2}:TCP = "{port2}:TCP:*:Enabled:TCP {port2}"
Step 6
Search and delete these folders
- %Application Data%\Microsoft\Address Book
- %User Temp%\{random folder name}
Step 7
Search and delete these files
- %Application Data%\{random filename 2}.{random}
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.YUNKH. 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
The following created registry key(s) cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present keys with a backup of the system registry. Note that the said key(s) do not have to be deleted since it won't be harmful to the system:
- HKEY_CURRENT_USER\Software\Microsoft\{random}
Step 10
Scan your computer with your Trend Micro product to delete files detected as TSPY_ZBOT.YUNKH. 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.
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