WORM_AINSLOT.AV
Worm:Win32/Ainslot.A (Microsoft); Generic Dropper!1hk (McAfee); Trojan.Gen (Symantec); Trojan-Dropper.Win32.Injector.bwto (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Generic.KDV.278972 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm 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 worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
system32 = "%User Profile%\Application Data\sun.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
system32 = "%User Profile%\Application Data\sun.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{3EDF9DEB-4DFE-D5EA-CADB-0F60FD1BFFF6}
StubPath = "%User Profile%\Application Data\sun.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\{3EDF9DEB-4DFE-D5EA-CADB-0F60FD1BFFF6}
StubPath = "%User Profile%\Application Data\sun.exe"
Other System Modifications
This worm adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\run
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{3EDF9DEB-4DFE-D5EA-CADB-0F60FD1BFFF6}
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Active Setup\Installed Components\{3EDF9DEB-4DFE-D5EA-CADB-0F60FD1BFFF6}
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
SrvID\ID
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
INSTALL\DATE
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\run
system32 = "%User Profile%\Application Data\sun.exe"
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
SrvID\ID
ZYX5CSTSSE = "SuN"
HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
INSTALL\DATE
ZYX5CSTSSE = "January 17, 2012"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DoNotAllowExceptions = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name}.exe = "{malware path and file name}.exe:*:enabled:windows messanger"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%User Profile%\Application Data\sun.exe = "{random characters}"
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer
- run
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
- {3EDF9DEB-4DFE-D5EA-CADB-0F60FD1BFFF6}
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Active Setup\Installed Components
- {3EDF9DEB-4DFE-D5EA-CADB-0F60FD1BFFF6}
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\SrvID
- ID
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\INSTALL
- DATE
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- system32 = "%User Profile%\Application Data\sun.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- system32 = "%User Profile%\Application Data\sun.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{3EDF9DEB-4DFE-D5EA-CADB-0F60FD1BFFF6}
- StubPath = "%User Profile%\Application Data\sun.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Active Setup\Installed Components\{3EDF9DEB-4DFE-D5EA-CADB-0F60FD1BFFF6}
- StubPath = "%User Profile%\Application Data\sun.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\run
- system32 = "%User Profile%\Application Data\sun.exe"
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\SrvID\ID
- ZYX5CSTSSE = "SuN"
- In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\INSTALL\DATE
- ZYX5CSTSSE = "January 17, 2012"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- DoNotAllowExceptions = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- {malware path and file name}.exe = "{malware path and file name}.exe:*:enabled:windows messanger"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- %User Profile%\Application Data\sun.exe = "{random characters}"
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_AINSLOT.AV. 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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