- Threat Encyclopedia
- Malware
- BKDR_SHOTODOR.A
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Downloaded from the Internet, Dropped by other malware
This malware makes use of “garbage” strings, which in actual hides the malicious code. The said malicious code is an obfuscated AutoIt script.
To get a one-glance comprehensive view of the behavior of this Backdoor, refer to the Threat Diagram shown below.
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.
It adds certain registry entries to disable the Task Manager. This action prevents users from terminating the malware process, which can usually be done via the Task Manager.
It executes commands from a remote malicious user, effectively compromising the affected system.
It modifies the Internet Explorer Zone Settings.
It logs a user's keystrokes to steal information.
1,235,361 bytes
EXE
Yes
08 Oct 2013
Connects to URLs/IPs, Steals information, Compromises system security
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 drops the following file(s)/component(s):
(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.)
It drops the following non-malicious file:
(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.)
It creates the following folders:
(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.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
It stays memory-resident by injecting codes into the following processes:
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\RunOnce
WXVIL = "%User Profile%\WXVIL\start.vbs"
It drops the following files:
(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.)
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\DC3_FEXEC
It adds the following registry entries to disable the Task Manager:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = "1"
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
It connects to the following URL(s) to send and receive commands from a remote malicious user:
Web Browser Home Page and Search Page Modification
This backdoor modifies the Internet Explorer Zone Settings.
Information Theft
This backdoor gathers the following data:
It logs a user's keystrokes to steal information.
Stolen Information
The stolen information is saved in the following file:
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
9.300
10.328.01
08 Oct 2013
10.329.00
09 Oct 2013
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 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.
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.
Step 5
Search and delete these folders
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_SHOTODOR.A. 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.