TSPY_ZBOT.TYR
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Spyware
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This spyware arrives as an attachment to spammed messages pretending to be from Fidelity Investments.
To get a one-glance comprehensive view of the behavior of this Spyware, refer to the Threat Diagram shown below.
This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It may be unknowingly downloaded by a user while visiting malicious websites.
It is injected into all running processes to remain memory resident.
It modifies the Internet Explorer Zone Settings.
As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Arrival Details
This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This spyware drops the following files:
- %Application Data%\{random2}\{random}.{random ext}
(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 copies of itself into the affected system:
- %Application Data%\{random1}\{random}.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 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 is injected into all running processes to remain memory resident.
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
{GUID} = "%Application Data%\{random1}\{random}.exe"
Other System Modifications
This spyware adds the following registry keys as part of its installation routine:
HKEY_CURRENT_USER\Software\Microsoft\
{random}
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}epage.ru/april.php
As of this writing, the said sites are inaccessible.
NOTES:
It arrives as an attachment to spammed messages related to Fidelity Investments.
This spyware may monitor several finance-related institutions depending on the contents of the configuration file. The configuration file also contains the "drop zone" where it sends stolen information, URL where the configuration file can be downloaded, codes for web inject, and monitored URLs.
Currently, the configuration file is inaccessible.
SOLUTION
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.TYR
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
- {GUID} = %Application Data%\{random1}\{random}.exe
- {GUID} = %Application Data%\{random1}\{random}.exe
Step 5
Search and delete this file
- %Application Data%\{random2}\{random}.{random ext}
Step 6
Search and delete these folders
- %Application Data%\{random1}
- %Application Data%\{random2}
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.TYR. 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} cannot be identified by the users 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, {random} need not to be deleted since it won't cause the user system any harm. In deleting the created folders, please take note of the malware path of the file(s) detected earlier.
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