BKDR_BLADABINDI.YYSRO
Backdoor:MSIL/Bladabindi (Microsoft)
Windows
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
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 a copy of itself in the following folders using different file names:
- %User Profile%\server.exe
- %User Startup%\4610427f9cc5281defe9550a924fd4ea.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.. %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)
It terminates the execution of the copy it initially executed and executes the copy it drops instead.
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
4610427f9cc5281defe9550a924fd4ea = “%User Profile%\server.exe”
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
4610427f9cc5281defe9550a924fd4ea = “%User Profile%\server.exe”
Other System Modifications
This Backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\4610427f9cc5281defe9550a924fd4ea
It adds the following registry entries:
HKEY_CURRENT_USER\Environment
SEE_MASK_NOZONECHECKS = "1"
HKEY_CURRENT_USER\Software\4610427f9cc5281defe9550a924fd4ea
US = "@"
Propagation
This Backdoor drops the following copy of itself in all physical and removable drives:
- {Drive Letter}\! My Picutre.SCR
Dropping Routine
This Backdoor drops the following files:
- %User Profile%\server.exe.tmp
(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 Details
This Backdoor connects to the following possibly malicious URL:
- zahora.{BLOCKED}p.biz
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 2
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Terminate a process file/s detected as BKDR_BLADABINDI.YYSRO
*Note: If the detected file/s is/are not displayed in theWindows Task Manager, continue doing the next steps.
Step 4
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.
- HKEY_CURRENT_USER\Software\4610427f9cc5281defe9550a924fd4ea
Step 5
Delete these 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_CURRENT_USER\Environment
- SEE_MASK_NOZONECHECKS = “1”
- SEE_MASK_NOZONECHECKS = “1”
- In HKEY_CURRENT_USER\Software\4610427f9cc5281defe9550a924fd4ea
- US = “@”
- US = “@”
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- 4610427f9cc5281defe9550a924fd4ea = “%User Profile%\server.exe”
- 4610427f9cc5281defe9550a924fd4ea = “%User Profile%\server.exe”
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- 4610427f9cc5281defe9550a924fd4ea = “%User Profile%\server.exe”
- 4610427f9cc5281defe9550a924fd4ea = “%User Profile%\server.exe”
Step 6
Search and delete these files
- %User Profile%\server.exe.tmp
Step 7
Scan your computer with your Trend Micro product to delete files detected as BKDR_BLADABINDI.YYSRO. 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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