TSPY_ZBOT.BIA
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Spyware
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Spammed via email
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 arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It does not have any propagation routine.
It does not have any backdoor routine.
It modifies the Internet Explorer Zone Settings.
As of this writing, the said sites are inaccessible.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
189,952 bytes
EXE
Yes
17 Nov 2011
Downloads files
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.
It arrives as an attachment to the following email messages spammed by other malware/grayware or malicious users:
Installation
This spyware drops the following copies of itself into the affected system:
- %Application Data%\{random folder 1}\{random characters}.exe
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
It drops the following component file(s):
- %Application Data%\{random folder 2}\{random characters}.{random characters}
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
It creates the following folders:
- %Application Data%\{random1}
- %Application Data%\{random2}
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
It stays memory-resident by injecting codes into the following processes:
- All running processes
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 CLSID} = "%Application Data%\{random folder 1}\{malware file name}.exe"
Other System Modifications
This spyware adds the following registry keys as part of its installation routine:
HKEY_CURRENT_USER\Software\Microsoft\
{random characters}
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"
Propagation
This spyware does not have any propagation routine.
Backdoor Routine
This spyware does not have any backdoor routine.
Web Browser Home Page and Search Page Modification
This spyware modifies the Internet Explorer Zone Settings.
Download Routine
This spyware connects to the following URL(s) to download its configuration file:
- http://{BLOCKED}n.ru/become.php
As of this writing, the said sites are inaccessible.
Other Details
This spyware deletes the initially executed copy of itself
NOTES:
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.
This spyware does not exploit any vulnerability.
Rootkit Capabilities
This spyware does not have rootkit capabilities.
SOLUTION
9.200
8.580.08
17 Nov 2011
8.581.00
18 Nov 2011
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Scan your computer with your Trend Micro product and note files detected as TSPY_ZBOT.BIA
Step 3
Restart in Safe Mode
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
- {random CLSID} = "%Application Data%\{random folder 1}\{malware file name}.exe"
- {random CLSID} = "%Application Data%\{random folder 1}\{malware file name}.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"
Step 5
Search and delete these folders
- %Application Data%\{random1}
- %Application Data%\{random2}
Step 6
Reset Internet security settings
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.BIA. 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.
NOTES:
The created registry key HKEY_CURRENT_USER\Software\Microsoft\{random characters} 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 if the users have one. Note that the key need not to be deleted since it won't cause the user system any harm.
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