TSPY_ZBOT.SM16
PWS:Win32/Zbot.gen!AJ (Microsoft), PWS-Zbot.gen.aow (McAfee)
Windows 2000, Windows XP, Windows Server 2003, Windows 7
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.
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 copies of itself into the affected system:
- %User Profile%\Application Data\{random1}\{random}.exe
- %Application Data%\{random1}\{random}.exe (Windows 7 only)
(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.)
It creates the following folders:
- %User Profile%\Application Data\{random1}
- %User Profile%\Application Data\{random2}
- %User Profile%\Application Data\{random3}
- %Application Data%\{random1} (Windows 7 only)
- %Application Data%\{random2} (Windows 7 only)
- %Application Data%\{random3} (Windows 7 only)
(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.)
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 Profile%\Application Data\{random1}\{random}.exe""
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random} = "%Application Data%\{random1}\{random}.exe" (Windows 7 only)
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
{random}
Dropping Routine
This spyware drops the following files:
- %User Profile%\Application Data\{random2}\{random}.{random}
- %User Profile%\Application Data\{random3}\{random}.{random}
- %Application Data%\{random2}\{random}.{random} (Windows 7 only)
- %Application Data%\{random3}\{random}.{random} (Windows 7 only)
(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 connects to the following possibly malicious URL:
- http://{BLOCKED}7.cc/link.php|file=config.bin
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.
- HKEY_CURRENT_USER\Software\Microsoft\{random}
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} = ""%User Profile%\Application Data\{random1}\{random}.exe""
- {random} = ""%User Profile%\Application Data\{random1}\{random}.exe""
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random} = "%Application Data%\{random1}\{random}.exe" (Windows 7 only)
- {random} = "%Application Data%\{random1}\{random}.exe" (Windows 7 only)
Step 5
Search and delete these folders
- %User Profile%\Application Data\{random1}
- %User Profile%\Application Data\{random2}
- %User Profile%\Application Data\{random3}
- %Application Data%\{random1} (Windows 7 only)
- %Application Data%\{random2} (Windows 7 only)
- %Application Data%\{random3} (Windows 7 only)
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.SM16. 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 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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