TROJ_ZBOT.MGZ
PWS:Win32/Zbot (Microsoft); Trojan-Spy.Win32.Zbot.hxar (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)
Windows 2000, Windows XP, Windows Server 2003
![](/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.
It deletes itself after execution.
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\Saseul
(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 Trojan 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%\Saseul\wauzko.exe"
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Weviga
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Weviga
hh5069f = "SSJzev0D?_CHAR(0x03)_?"
HKEY_CURRENT_USER\Software\Microsoft\
Weviga
12dj66bh = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Weviga
12dj66bh = "7a16222c"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
22346:UDP = "22346:UDP:*:Enabled:UDP 22346"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
15558:TCP = "15558:TCP:*:Enabled:TCP 15558"
HKEY_CURRENT_USER\Software\Microsoft\
Weviga
2j93i1jd = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Weviga
1aidgi8g = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Weviga
fijbf2g = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Weviga
fijbf2g = "{random characters}"
HKEY_CURRENT_USER\Software\Microsoft\
Weviga
1aidgi8g = "{random characters}"
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\
Weviga
12dj66bh = "bCIWeg==_CHAR(0x07)__CHAR(0x03)_T_CHAR(0x08)_"
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 Trojan drops the following files:
- %User Profile%\Application Data\Saseul
- %User Profile%\Saseul\wauzko.exe
- %Application Data%\voyvy.toi
(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 Trojan 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
- Weviga
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%\Saseul\wauzko.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Weviga
- hh5069f = "SSJzev0D?_CHAR(0x03)_?"
- In HKEY_CURRENT_USER\Software\Microsoft\Weviga
- 12dj66bh = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Weviga
- 12dj66bh = "7a16222c"
- 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
- 22346:UDP = "22346:UDP:*:Enabled:UDP 22346"
- 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
- 15558:TCP = "15558:TCP:*:Enabled:TCP 15558"
- In HKEY_CURRENT_USER\Software\Microsoft\Weviga
- 2j93i1jd = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Weviga
- 1aidgi8g = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Weviga
- fijbf2g = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Weviga
- fijbf2g = "{random characters}"
- In HKEY_CURRENT_USER\Software\Microsoft\Weviga
- 1aidgi8g = "{random characters}"
- 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\Weviga
- 12dj66bh = "bCIWeg==_CHAR(0x07)__CHAR(0x03)_T_CHAR(0x08)_"
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\Saseul
- %User Profile%\Saseul\wauzko.exe
- %Application Data%\voyvy.toi
Step 7
Search and delete this folder
- %User Profile%\Application Data\Saseul
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_ZBOT.MGZ. 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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