TSPY_ZBOT.YUYAFX
PWS:Win32/Bamkro.A (Microsoft); Backdoor.Trojan (Symantec); Trojan-Spy.Win32.Zbot.vtgv (Kaspersky); Worm.Win32.AInfBot.l (v) (Sunbelt); Trojan horse Packed2_c.BZQU (AVG)
Windows
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%\Speech\conhost.exe
(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.)
It creates the following folders:
- %User Profile%\Microsoft\Speech
(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 spyware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Update = "%User Profile%\Speech\conhost.exe"
Other System Modifications
This spyware deletes the following files:
- %System%\wuaumgr.exe
- %User Profile%\Network\svchost.exe
- %User Profile%\Microsoft\svchost.exe
- %User Profile%\Microsoft\conhost.exe
- %System Root%\cer.dat
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %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.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
It adds the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Share
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\
Microsoft\Windows\CurrentVersion\
Run
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Share
del = "%System Root%\cer.dat"
HKEY_CURRENT_USER\Software\Microsoft\
Share
path = "%User Profile%\Speech\conhost.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Share
ver = "138"
HKEY_CURRENT_USER\Software\Microsoft\
Share
scrpt = "{random values}"
Dropping Routine
This spyware drops the following files:
- %Windows%\system32111.dat
- %System%\drivers\npf.sys
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
Other Details
This spyware connects to the following possibly malicious URL:
- http://{BLOCKED}m19.ml
- http://www.{BLOCKED}myip.org/n09230945.asp
- http://www.{BLOCKED}myip.org/simple
- http://{BLOCKED}m19.ml/plugin/np.dat?v=120109
- http://www.{BLOCKED}myip.org/plugin/np.dat?v=155890
- {BLOCKED}0.1
- {BLOCKED}.100.116
- {BLOCKED}.101.116
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
- Share
- In HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion
- Run
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
- Update = "%User Profile%\Speech\conhost.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Share
- del = "%System Root%\cer.dat"
- In HKEY_CURRENT_USER\Software\Microsoft\Share
- path = "%User Profile%\Speech\conhost.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Share
- ver = "138"
- In HKEY_CURRENT_USER\Software\Microsoft\Share
- scrpt = "{random values}"
Step 5
Search and delete these components
- %Windows%\system32111.dat
- %System%\drivers\npf.sys
Step 6
Search and delete this folder
- %User Profile%\Microsoft\Speech
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.YUYAFX. 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.
Step 8
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %System%\wuaumgr.exe
- %User Profile%\Network\svchost.exe
- %User Profile%\Microsoft\svchost.exe
- %User Profile%\Microsoft\conhost.exe
- %System Root%\cer.dat
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