WORM_DOWNAD.EY
Worm:Win32/Conficker.B (Microsoft),Net-Worm.Win32.Kido.ih (Kaspersky),W32.Downadup (Symantec)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives via removable drives. It may be dropped by other malware.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
161,814 bytes
DLL
Yes
02 Jan 2014
Arrival Details
This worm arrives via removable drives.
It may be dropped by other malware.
Installation
This worm drops the following copies of itself into the affected system:
- %System%\{random}.dll
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
Other System Modifications
This worm modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\BITS
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ERSvc
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wscsvc
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wuauserv
Start = "4"
(Note: The default value data of the said registry entry is 2.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"
(Note: The default value data of the said registry entry is 1.)
It creates the following registry entry(ies) to bypass Windows Firewall:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{random port number}:TCP = "{random port number}:TCP:*:Enabled:{random value}"
Propagation
This worm creates the following folders in all removable drives:
- {removable drive letter}:\RECYCLER
- {removable drive letter}:\RECYCLER\{SID}
It drops the following copy(ies) of itself in all removable drives:
- {removable drive letter}:\RECYCLER\{SID}\{random characters}
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
;{garbage characters}
[AUTorUN
;{garbage characters}
AcTION=Open folder to view files
;{garbage characters}
icon=%syStEmrOot%\sySTEM32\sHELL32.Dll ,4
;{garbage characters}
shelLExECUte=RuNdLl32.EXE .\RECYCLER\{SID}\{random characters},{value}
;{garbage characters}
Other Details
This worm connects to the following URL(s) to get the affected system's IP address:
- http://www.whatsmyipaddress.com
- http://checkip.dyndns.org
NOTES:
Upon execution, it opens a window which displays the files under the malware path's root drive to hide its malicious routines from the user.
It also modifies its file attributes to Read-only and Hidden after execution.
SOLUTION
9.700
10.516.02
02 Jan 2014
10.517.00
03 Jan 2014
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 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\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {random port number}:TCP = "{random port number}:TCP:*:Enabled:{random value}"
- {random port number}:TCP = "{random port number}:TCP:*:Enabled:{random value}"
Step 4
Restore this modified 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\Explorer\Advanced
- From: Hidden = "2"
To: Hidden = 1
- From: Hidden = "2"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = "0"
To: CheckedValue = 1
- From: CheckedValue = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\BITS
- From: Start = "4"
To: Start = 2
- From: Start = "4"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ERSvc
- From: Start = "4"
To: Start = 2
- From: Start = "4"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wscsvc
- From: Start = "4"
To: Start = 2
- From: Start = "4"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wuauserv
- From: Start = "4"
To: Start = 2
- From: Start = "4"
Step 5
Search and delete these folders
- {removable drive letter}:\RECYCLER
Step 6
Search and delete AUTORUN.INF files created by WORM_DOWNAD.EY that contain these strings
;{garbage characters}
[Autorun
;{garbage characters}
AcTION=Open folder to view files
;{garbage characters}
icon=%Systemroot%\sySTEM32\sHELL32.Dll ,4
;{garbage characters}
shelLExECUte=RuNdLl32.EXE .\RECYCLER\{SID}\{random characters},{value}
;{garbage characters}
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_DOWNAD.EY. 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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