WORM_AUTORUN.FCM
Windows 2000, XP, Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This worm executes then deletes itself afterward.
It adds registry entries to enable its automatic execution at every system startup.
It modifies registry entries to hide files with System and Read-only attributes.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
TECHNICAL DETAILS
Installation
This worm drops the following component file(s):
- %User Temp%\apiqq0.dll - also detected as WORM_AUTORUN.FCM
(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 drops the following copies of itself into the affected system:
- %User Temp%\apiqq.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.)
It executes then deletes itself afterward.
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
api32 = %User Temp%\apiqq.exe
Other System Modifications
This worm adds the following registry keys as part of its installation routine:
HKEY_CLASSES_ROOT\CLSID\MADOWN
It modifies the following registry entries to hide files with System and Read-only 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
ShowSuperHidden = 0
(Note: The default value data of the said registry entry is 1.)
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.)
Propagation
This worm drops the following copy of itself in all physical and removable drives:
- r3q63rok.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:
[AutoRun]
open=r3q63rok.exe
shell\open\Command=r3q63rok.exe
Download Routine
This worm accesses the following websites to download files:
- http://www.{BLOCKED}rt.com/1mg/am1.rar
- http://www.{BLOCKED}f.com/1mg/am.rar
- http://www.{BLOCKED}f.com/1mg/am1.rar
Trend Micro detects the dowloaded file as:
- TSPY_FRETHOG.ML
It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
SOLUTION
Step 1
For Windows ME and XP users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Remove malware files dropped/downloaded by WORM_AUTORUN.FCM
- TSPY_FRETHOG.ML
Step 3
Restart in Safe Mode
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
- api32 = %User Temp%\apiqq.exe
- api32 = %User Temp%\apiqq.exe
Step 5
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: 1
- From: Hidden = 2
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: ShowSuperHidden = 0
To: 1
- From: ShowSuperHidden = 0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = 0
To: 1
- From: CheckedValue = 0
Step 6
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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.
- In HKEY_CLASSES_ROOT\CLSID
- MADOWN
- MADOWN
Step 7
Search and delete AUTORUN.INF files created by WORM_AUTORUN.FCM that contain these strings
Step 8
Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.FCM 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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