BKDR_GBOT.HN
Backdoor:Win32/Cycbot.G (Microsoft); BackDoor-EXI.gen.aa (McAfee); Backdoor.Trojan (Symantec); Backdoor.Win32.Gbot.qvo (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Gen:Variant.Kazy.48327 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This backdoor 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
293,888 bytes
EXE
Yes
27 Nov 2012
Arrival Details
This backdoor 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 backdoor creates the following folders:
- %User Profile%\Application Data\68AD0
- %Program Files%\LP
- %Program Files%\LP\2846
- %User Profile%\CryptnetUrlCache\MetaData
- %User Profile%\Microsoft\CryptnetUrlCache
- %User Profile%\CryptnetUrlCache\Content
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
056.exe = "%Program Files%\LP\2846\056.exe"
Other System Modifications
This backdoor deletes the following folders:
- %User Profile%\My Documents\My Pictures
- %Start Menu%\Programs\Administrative Tools
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu on Windows Vista and 7.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\WinRAR
It adds the following registry entries:
HKEY_CURRENT_USER\Software\WinRAR
HWID = "{random values}"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\wscsvc
Start = "3"
(Note: The default value data of the said registry entry is 2.)
Dropping Routine
This backdoor drops the following files:
- %Program Files%\LP\2846\1.tmp
- %Program Files%\LP\2846\056.exe
- %User Profile%\MetaData\7B2238AACCEDC3F1FFE8E7EB5F575EC9
- %User Profile%\Content\7B2238AACCEDC3F1FFE8E7EB5F575EC9
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
This report is generated via an automated analysis system.
SOLUTION
9.300
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_CURRENT_USER\Software
- WinRAR
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\Windows\CurrentVersion\Run
- 056.exe = "%Program Files%\LP\2846\056.exe"
- In HKEY_CURRENT_USER\Software\WinRAR
- HWID = "{random values}"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wscsvc
- From: Start = "3"
To: Start = ""2""
- From: Start = "3"
Step 6
Search and delete these components
- %Program Files%\LP\2846\1.tmp
- %Program Files%\LP\2846\056.exe
- %User Profile%\MetaData\7B2238AACCEDC3F1FFE8E7EB5F575EC9
- %User Profile%\Content\7B2238AACCEDC3F1FFE8E7EB5F575EC9
Step 7
Search and delete these folders
- %User Profile%\Application Data\68AD0
- %Program Files%\LP
- %Program Files%\LP\2846
- %User Profile%\CryptnetUrlCache\MetaData
- %User Profile%\Microsoft\CryptnetUrlCache
- %User Profile%\CryptnetUrlCache\Content
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_GBOT.HN. 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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