WORM_AUTORN.ZQLA
Symantec : W32.SillyFDC ; Microsoft : Worm:Win32/Autorun.WT
Windows 2000, XP, Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Copies itself in all available physical drives
This worm drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
TECHNICAL DETAILS
15,294,464 bytes
PE
Yes
09 Dec 2010
Modifies system registry, Drops files
Installation
This worm drops the following copies of itself into the affected system:
- %System Root%\Program{double space}Files\Windows Alerter\WinAlert.exe
- %System Root%\Program{double space}Files\Windows Common Files\Commgr.exe
- %System Root%\RECYCLER\{SID}\WinSysApp.exe
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
It drops the following non-malicious files:
- %System Root%\RECYCLER\{SID}\bnf0342
- %System Root%\RECYCLER\{SID}\info
- %System Root%\RECYCLER\{SID}\wndsvc.dll
- %REMOVABLE DRIVE%\RECYCLER\desktop.ini
(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%\Program{double space}Files
- %System Root%\Program{double space}Files\Windows Alerter
- %System Root%\Program{double space}Files\Windows Common Files
- %System Root%\RECYCLER\{SID}
- %Current%\autorun.inf
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
WindowMessenger = %System Root%\RECYCLER\{SID}\WinSysApp.exe
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Alerter = %System Root%\Program{double space}Files\Windows Alerter\WinAlert.exe
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Common Files Manager = %System Root%\Program{double space}Files\Windows Common Files\Commgr.exe
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WindowMessenger = %System Root%\RECYCLER\{SID}\WinSysApp.exe
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows Alerter = %System Root%\Program{double space}Files\Windows Alerter\WinAlert.exe
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows Common Files Manager = %System Root%\Program{double space}Files\Windows Common Files\Commgr.exe
Other System Modifications
This worm modifies the following registry entries to hide files with Hidden attributes:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = 1
(Note: The default value data of the said registry entry is 0.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 0
(Note: The default value data of the said registry entry is 1.)
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- recycler{spaces}.exe
- [DRIVE]:\RECYCLER\{random}.exe
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:
[ A u t o r u n ]
O p e n = R E C Y C L E R \{random}. e x e
E x p l o r e = R E C Y C L E R \{random}. e x e
A u t o P l a y = R E C Y C L E R \{random}. e x e
s h e l l \ O p e n \ C o m m a n d = R E C Y C L E R \{random}. e x e
s h e l l \ O p e n \ D e f a u l t = 1
s h e l l \ E x p l o r e \ c o m m a n d = R E C Y C L E R \{random}. e x e
s h e l l \ A u t o p l a y \ C o m m a n d = R E C Y C L E R \{random}. e x e
Other Details
This worm does the following:
- Upon execution, it creates a folder named "autorun.inf" in its current directory and opens it in order to hide its malicious routines from the user.
SOLUTION
8.900
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
Identify and terminate files detected as WORM_AUTORN.ZQLA
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
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\Microsoft\Windows\CurrentVersion\Run
- WindowMessenger = %System Root%\RECYCLER\{SID}\WinSysApp.exe
- WindowMessenger = %System Root%\RECYCLER\{SID}\WinSysApp.exe
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Windows Alerter = %System Root%\Program{double space}Files\Windows Alerter\WinAlert.exe
- Windows Alerter = %System Root%\Program{double space}Files\Windows Alerter\WinAlert.exe
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Windows Common Files Manager = %System Root%\Program{double space}Files\Windows Common Files\Commgr.exe
- Windows Common Files Manager = %System Root%\Program{double space}Files\Windows Common Files\Commgr.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- WindowMessenger = %System Root%\RECYCLER\{SID}\WinSysApp.exe
- WindowMessenger = %System Root%\RECYCLER\{SID}\WinSysApp.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Windows Alerter = %System Root%\Program{double space}Files\Windows Alerter\WinAlert.exe
- Windows Alerter = %System Root%\Program{double space}Files\Windows Alerter\WinAlert.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Windows Common Files Manager = %System Root%\Program{double space}Files\Windows Common Files\Commgr.exe
- Windows Common Files Manager = %System Root%\Program{double space}Files\Windows Common Files\Commgr.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 = 1
- From: Hidden = 2
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: HideFileExt = 1
To: HideFileExt = 0
- From: HideFileExt = 1
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: ShowSuperHidden = 0
To: HideFileExt = 1
- From: ShowSuperHidden = 0
Step 5
Search and delete these folders
Step 6
Search and delete AUTORUN.INF files created by WORM_AUTORN.ZQLA that contain these strings
Step 7
Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORN.ZQLA. 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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