TROJ_ZBOT.FZE
Trojan-Spy.Win32.Zbot.ckwn (Kaspersky), PWS:Win32/Zbot.gen!Y (Microsoft)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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.
As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
187,904 bytes
EXE
UPX
No
22 Oct 2011
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:
- %Application Data%\{random folder 1}\{random file name 1}.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 files:
- %Application Data%\{random folder 2}\{random file name 2}.{random extension}
(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%\{random folder 1}
- %Application Data%\{random folder 2}
(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 the following processes running in memory:
- ctfmon.exe
- dwm.exe
- explorer.exe
- rdpclip.exe
- taskeng.exe
- taskhost.exe
- wscntfy.exe
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
{CLSID} = "%Application Data%\{random folder 1}\{random file name 1}.exe"
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
{random key}
Download Routine
This spyware connects to the following URL(s) to download its configuration file:
- http://{BLOCKED}p.ru/search/newfile11.bin
As of this writing, the said sites are inaccessible.
SOLUTION
9.200
8.517.01
22 Oct 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 TROJ_ZBOT.FZE
Step 3
Restart in Safe Mode
Step 4
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\
- {random key}
- {random key}
Step 5
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
- {CLSID} = "%Application Data%\{random folder 1}\{random file name 1}.exe"
- {CLSID} = "%Application Data%\{random folder 1}\{random file name 1}.exe"
Step 6
Search and delete these folders
- %Application Data%\{random folder 1}
- %Application Data%\{random folder 2}
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_ZBOT.FZE. 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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