WORM_AUTORUN.BY
Worm:Win32/Usbwatch.B (Microsoft); [00002128.EXE]:W32/CEP.worm (McAfee); W32.SillyFDC (Symantec); Worm.Win32.AutoRun.duv, Worm.Win32.AutoRun.duv (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Worm.Generic.87735 (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.
Installation
This worm drops the following copies of itself into the affected system:
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003\ex.dat
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
It creates the following folders:
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003\send
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
Other System Modifications
This worm deletes the following files:
- %User Temp%\1.hiv
- %User Temp%\2.hiv
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\IExplorer
HKEY_LOCAL_MACHINE\Software\IExplorer
It adds the following registry entries:
HKEY_CURRENT_USER\Software\IExplorer
SCMTool = "%User Temp%\wauclt.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\IExplorer
SCMTool = "%User Temp%\wauclt.exe"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2
(Note: The default value data of the said registry entry is 2.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoDriveTypeAutoRun = ff
(Note: The default value data of the said registry entry is 91.)
Dropping Routine
This worm drops the following files:
- %User Temp%\devwinmgmt.msc
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003\desktop.ini
- %User Temp%\wauclt.exe
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003\u.dat
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003\send\sysinf
- %User Temp%\msdtr.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
Other Details
This worm connects to the following possibly malicious URL:
- http://{BLOCKED}4.117.19:80/sb.php?id=0304591161679F1222
- http://{BLOCKED}4.117.10:80/sb.php?id=0305601161679F1222
This report is generated via an automated analysis system.
SOLUTION
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
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
- IExplorer
- In HKEY_LOCAL_MACHINE\Software
- IExplorer
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_CURRENT_USER\Software\IExplorer
- SCMTool="%User Temp%\wauclt.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\IExplorer
- SCMTool="%User Temp%\wauclt.exe"
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=2
- From: Hidden=2
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- From: NoDriveTypeAutoRun=ff
To: NoDriveTypeAutoRun=91
- From: NoDriveTypeAutoRun=ff
Step 5
Search and delete these folders
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003\send
Step 6
Search and delete these files
- %User Temp%\devwinmgmt.msc
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003\desktop.ini
- %User Temp%\wauclt.exe
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003\u.dat
- %System Root%\RECYCLER\Z-1-6-22-1085480564-571221492-571812059-1003\send\sysinf
- %User Temp%\msdtr.exe
Step 7
Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.BY. 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.
- %User Temp%\1.hiv
- %User Temp%\2.hiv
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