WORM_GAOBOT.AI
VirTool:Win32/VBInject.AQ (Microsoft); W32/Hamweq.worm.aq (McAfee); W32.IRCBot (Symantec); Trojan.Win32.Agent2.jab, Trojan.Win32.Agent2.jab (Kaspersky); Trojan.Win32.VBInject.gen (v) (Sunbelt); Trojan.Generic.2265348 (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
200,704 bytes
EXE
Yes
02 Jul 2012
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\k-1-3542-4232123213-7676767-8888886\hn.exe
(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
- %System Root%\RECYCLER\k-1-3542-4232123213-7676767-8888886
(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_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{23KLN5J0-4OPM-11WE-AAX5-24EF1F387232}
StubPath = "%System Root%\RECYCLER\k-1-3542-4232123213-7676767-8888886\hn.exe"
Other System Modifications
This worm deletes the following files:
- %User Temp%\test.htm
- %System Root%\RECYCLER\k-1-3542-4232123213-7676767-8888886\hn.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.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Active Setup\Installed Components\{23KLN5J0-4OPM-11WE-AAX5-24EF1F387232}
It deletes the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\{23KLN5J0-4OPM-11WE-AAX5-24EF1F387232}
Dropping Routine
This worm drops the following files:
- %System Root%\RECYCLER\k-1-3542-4232123213-7676767-8888886\Desktop.ini
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
This report is generated via an automated analysis system.
SOLUTION
9.200
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
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\Active Setup\Installed Components
- {23KLN5J0-4OPM-11WE-AAX5-24EF1F387232}
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\Active Setup\Installed Components\{23KLN5J0-4OPM-11WE-AAX5-24EF1F387232}
- StubPath = "%System Root%\RECYCLER\k-1-3542-4232123213-7676767-8888886\hn.exe"
Step 5
Search and delete this file
- %System Root%\RECYCLER\k-1-3542-4232123213-7676767-8888886\Desktop.ini
Step 6
Search and delete these folders
- %System Root%\RECYCLER
- %System Root%\RECYCLER\k-1-3542-4232123213-7676767-8888886
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_GAOBOT.AI. 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%\test.htm
- %System Root%\RECYCLER\k-1-3542-4232123213-7676767-8888886\hn.exe
Step 9
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_CURRENT_USER\Software\Microsoft\Active Setup\Installed Components
- {23KLN5J0-4OPM-11WE-AAX5-24EF1F387232}
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