BKDR_SIMBOT.SME
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This backdoor may be dropped by other malware.
It scans the computer for registry keys related to antivirus and security applications. This action allows the malware to possibly avoid detection in the computer.
It executes commands from a remote malicious user, effectively compromising the affected system. It connects to a website to send and receive information.
TECHNICAL DETAILS
Arrival Details
This backdoor may be dropped by the following malware:
- TROJ_ARTIEF.FT
Installation
This backdoor drops the following copies of itself into the affected system:
- %User Profile%\Local Settings\{random}.exe
(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.)
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random} = "%User Profile%\Local Settings\{random}.exe"
Other System Modifications
This backdoor scans the system for the following registry keys, which are related to antivirus and security applications:
HKEY_LOCAL_MACHINE\SOFTWARE\McAfee
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Download and execute files
- Execute a DOS command sent by the remote user
- Send an encrypted copy of the content of a specified file to its C&C server
- Sleeps for a specified amount of time
It connects to the following websites to send and receive information:
- {BLOCKED}.103.58
NOTES:
If the registry, HKEY_LOCAL_MACHINE\SOFTWARE\McAfee is found on the system, it adds the following process:
- services.exe
It then injects itself into the said process as part of its memory residency routine.
If the registry is not found, it adds the following process:
- svchost.exe
It injects itself into that process as part of its memory residency routine.
It communicates with its C&C server by sending the following HTTP request:
- http://{C&C}/{random characters}.php?id={encoded adapter information of the affected machine}
The {random} file name of dropped copy/registry value name above can be any of the inactive services on the system.
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
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
- {random} = %User Profile%\Local Settings\{random}.exe
- {random} = %User Profile%\Local Settings\{random}.exe
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_SIMBOT.SME. 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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