TSPY_ZBOT.KHT
PWS:Win32/Zbot.gen!AL (Microsoft); PWS-Zbot.gen.aua (McAfee); Trojan-Spy.Win32.Zbot.igxk (Kaspersky)
Windows 2000, Windows XP, Windows Server 2003
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.
It deletes itself after execution.
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 creates the following folders:
- %User Profile%\Application Data\Avabcy
(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.)
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
{58C4EBA0-47A8-AD40-8C85-A85A94978B48} = "%User Profile%\Avabcy\imofoh.exe"
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
253ic6d3 = "OMV6nPa8fFNOfvQUaXI=?_CHAR(0x06)_?"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
2a0d5ei1 = "9c19c55a"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
2a0d5ei1 = "W8UZnA==?"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
25848:UDP = "25848:UDP:*:Enabled:UDP 25848"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
28014:TCP = "28014:TCP:*:Enabled:TCP 28014"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
2fb484d = "sqEZnPrRE1MkfsUU?_CHAR(0x05)_lF?r?rame"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
219i6f84 = "{random characters}"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
2feea4i4 = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
2feea4i4 = "{random characters}"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
219i6f84 = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
27c1j92d = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
859j6i6 = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
23g99i6j = "cce65d9"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager
Server ID = "4"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
FirstRun = "1"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkContactRefresh = "0"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkFolderRefresh = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Ugevb
2a0d5ei1 = "{random values}"
It modifies the following registry entries:
HKEY_CURRENT_USER\Identities
Last Username = "Main Identity"
(Note: The default value data of the said registry entry is Main Identity.)
HKEY_CURRENT_USER\Identities
Last User ID = "{341F68BA-C841-4200-A7B4-3D5CFF202166}"
(Note: The default value data of the said registry entry is {C0FE0177-5693-4537-9331-A7402AD82D40}.)
HKEY_CURRENT_USER\Identities
Identity Login = "9853"
(Note: The default value data of the said registry entry is 98053.)
HKEY_CURRENT_USER\Identities
Identity Ordinal = "2"
(Note: The default value data of the said registry entry is 1.)
Dropping Routine
This spyware drops the following files:
- %User Profile%\Application Data\Avabcy
- %User Profile%\Avabcy\imofoh.exe
- %Application Data%\asxa.deu
(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.. %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.)
Other Details
This spyware deletes itself after execution.
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
- Ugevb
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {58C4EBA0-47A8-AD40-8C85-A85A94978B48} = "%User Profile%\Avabcy\imofoh.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 253ic6d3 = "OMV6nPa8fFNOfvQUaXI=?_CHAR(0x06)_?"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 2a0d5ei1 = "9c19c55a"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 2a0d5ei1 = "W8UZnA==?"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DisableNotifications = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- 25848:UDP = "25848:UDP:*:Enabled:UDP 25848"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DisableNotifications = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- 28014:TCP = "28014:TCP:*:Enabled:TCP 28014"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 2fb484d = "sqEZnPrRE1MkfsUU?_CHAR(0x05)_lF?r?rame"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 219i6f84 = "{random characters}"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 2feea4i4 = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 2feea4i4 = "{random characters}"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 219i6f84 = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 27c1j92d = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 859j6i6 = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 23g99i6j = "cce65d9"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Account Manager
- Server ID = "4"
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4
- FirstRun = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4
- OlkContactRefresh = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4
- OlkFolderRefresh = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Ugevb
- 2a0d5ei1 = "{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\Identities
- From: Last Username = "Main Identity"
To: Last Username = ""Main Identity""
- From: Last Username = "Main Identity"
- In HKEY_CURRENT_USER\Identities
- From: Last User ID = "{341F68BA-C841-4200-A7B4-3D5CFF202166}"
To: Last User ID = ""{C0FE0177-5693-4537-9331-A7402AD82D40}""
- From: Last User ID = "{341F68BA-C841-4200-A7B4-3D5CFF202166}"
- In HKEY_CURRENT_USER\Identities
- From: Identity Login = "9853"
To: Identity Login = ""98053""
- From: Identity Login = "9853"
- In HKEY_CURRENT_USER\Identities
- From: Identity Ordinal = "2"
To: Identity Ordinal = ""1""
- From: Identity Ordinal = "2"
Step 6
Search and delete these components
- %User Profile%\Application Data\Avabcy
- %User Profile%\Avabcy\imofoh.exe
- %Application Data%\asxa.deu
Step 7
Search and delete this folder
- %User Profile%\Application Data\Avabcy
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.KHT. 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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